def __init__(self, n_question, batch_size, q_embed_dim, qa_embed_dim,
memory_size, memory_key_state_dim, memory_value_state_dim, final_fc_dim, student_num=None):
super(MODEL, self).__init__()
self.n_question = n_question
self.batch_size = batch_size
self.q_embed_dim = q_embed_dim
self.qa_embed_dim = qa_embed_dim
self.memory_size = memory_size
self.memory_key_state_dim = memory_key_state_dim
self.memory_value_state_dim = memory_value_state_dim
self.final_fc_dim = final_fc_dim
self.student_num = student_num
self.input_embed_linear = nn.Linear(self.q_embed_dim, self.final_fc_dim, bias=True)
self.read_embed_linear = nn.Linear(self.memory_value_state_dim + self.final_fc_dim, self.final_fc_dim, bias=True)
self.predict_linear = nn.Linear(self.final_fc_dim, 1, bias=True)
self.init_memory_key = nn.Parameter(torch.randn(self.memory_size, self.memory_key_state_dim))
nn.init.kaiming_normal_(self.init_memory_key)
self.init_memory_value = nn.Parameter(torch.randn(self.memory_size, self.memory_value_state_dim))
nn.init.kaiming_normal_(self.init_memory_value)
self.mem = DKVMN(memory_size=self.memory_size,
memory_key_state_dim=self.memory_key_state_dim,
memory_value_state_dim=self.memory_value_state_dim, init_memory_key=self.init_memory_key)
memory_value = nn.Parameter(torch.cat([self.init_memory_value.unsqueeze(0) for _ in range(batch_size)], 0).data)
self.mem.init_value_memory(memory_value)
self.q_embed = nn.Embedding(self.n_question + 1, self.q_embed_dim, padding_idx=0)
self.qa_embed = nn.Embedding(2 * self.n_question + 1, self.qa_embed_dim, padding_idx=0)
def __init__(self, args, sess, name='KT'):
self.args = args
self.name = name
self.sess = sess
# Initialize Memory
with tf.variable_scope('Memory'):
init_memory_key = tf.get_variable('key', [self.args.memory_size, self.args.memory_key_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_memory_value = tf.get_variable('value', [self.args.memory_size,self.args.memory_value_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Broadcast memory value tensor to match [batch size, memory size, memory state dim]
# First expand dim at axis 0 so that makes 'batch size' axis and tile it along 'batch size' axis
# tf.tile(inputs, multiples) : multiples length must be thes saame as the number of dimensions in input
# tf.stack takes a list and convert each element to a tensor
init_memory_value = tf.tile(tf.expand_dims(init_memory_value, 0), tf.stack([self.args.batch_size, 1, 1]))
print(init_memory_value.get_shape())
self.memory = DKVMN(self.args.memory_size, self.args.memory_key_state_dim, \
self.args.memory_value_state_dim, init_memory_key=init_memory_key, init_memory_value=init_memory_value, name='DKVMN')
# Embedding to [batch size, seq_len, memory_state_dim(d_k or d_v)]
with tf.variable_scope('Embedding'):
# A
self.q_embed_mtx = tf.get_variable('q_embed', [self.args.n_questions+1, self.args.memory_key_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
# B
self.qa_embed_mtx = tf.get_variable('qa_embed', [2*self.args.n_questions+1, self.args.memory_value_state_dim], initializer=tf.truncated_normal_initializer(stddev=0.1))
self.prediction = self.build_network(reuse_flag=False)
self.build_optimizer()
def init_memory(self):
with tf.variable_scope('Memory'):
init_memory_key = tf.get_variable('key', [self.args.memory_size, self.args.memory_key_state_dim], \
initializer=tf.random_normal_initializer(stddev=0.1))
#initializer=tf.truncated_normal_initializer(stddev=0.1))
self.init_memory_value = tf.get_variable('value', [self.args.memory_size,self.args.memory_value_state_dim], \
initializer=tf.random_normal_initializer(stddev=0.1))
#initializer=tf.truncated_normal_initializer(stddev=0.1))
#initializer=tf.random_uniform_initializer(minval=0.5, maxval=1.0))
# Broadcast memory value tensor to match [batch size, memory size, memory state dim]
# First expand dim at axis 0 so that makes 'batch size' axis and tile it along 'batch size' axis
# tf.tile(inputs, multiples) : multiples length must be thes saame as the number of dimensions in input
# tf.stack takes a list and convert each element to a tensor
stacked_init_memory_value = tf.tile(
tf.expand_dims(self.init_memory_value, 0),
tf.stack([self.args.batch_size, 1, 1]))
return DKVMN(self.args.memory_size, self.args.memory_key_state_dim, \
self.args.memory_value_state_dim, init_memory_key=init_memory_key, init_memory_value=stacked_init_memory_value, args=self.args, name='DKVMN')
class MODEL(nn.Module):
def __init__(self,
n_question,
batch_size,
q_embed_dim,
qa_embed_dim,
memory_size,
memory_key_state_dim,
memory_value_state_dim,
final_fc_dim,
student_num=None):
super(MODEL, self).__init__()
self.n_question = n_question
self.batch_size = batch_size
self.q_embed_dim = q_embed_dim
self.qa_embed_dim = qa_embed_dim
self.memory_size = memory_size
self.memory_key_state_dim = memory_key_state_dim
self.memory_value_state_dim = memory_value_state_dim
self.final_fc_dim = final_fc_dim
self.student_num = student_num
self.input_embed_linear = nn.Linear(self.q_embed_dim,
self.q_embed_dim,
bias=True)
self.read_embed_linear = nn.Linear(self.memory_value_state_dim +
self.q_embed_dim,
self.final_fc_dim,
bias=True)
self.predict_linear = nn.Linear(self.final_fc_dim, 1, bias=True)
self.init_memory_key = nn.Parameter(
torch.randn(self.memory_size, self.memory_key_state_dim))
nn.init.kaiming_normal_(self.init_memory_key)
self.init_memory_value = nn.Parameter(
torch.randn(self.memory_size, self.memory_value_state_dim))
nn.init.kaiming_normal_(self.init_memory_value)
self.mem = DKVMN(memory_size=self.memory_size,
memory_key_state_dim=self.memory_key_state_dim,
memory_value_state_dim=self.memory_value_state_dim,
init_memory_key=self.init_memory_key)
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data)
self.mem.init_value_memory(memory_value)
# 题目序号从1开始
# nn.embedding输入是一个下标的列标，输出是对应的嵌入
self.q_embed = nn.Embedding(self.n_question + 1,
self.q_embed_dim,
padding_idx=0)
self.qa_embed = nn.Embedding(2 * self.n_question + 1,
self.qa_embed_dim,
padding_idx=0)
def init_params(self):
nn.init.kaiming_normal_(self.predict_linear.weight)
nn.init.kaiming_normal_(self.read_embed_linear.weight)
nn.init.constant_(self.read_embed_linear.bias, 0)
nn.init.constant_(self.predict_linear.bias, 0)
# nn.init.constant(self.input_embed_linear.bias, 0)
# nn.init.normal(self.input_embed_linear.weight, std=0.02)
def init_embeddings(self):
nn.init.kaiming_normal_(self.q_embed.weight)
nn.init.kaiming_normal_(self.qa_embed.weight)
def forward(self, q_data, qa_data, target, student_id=None):
batch_size = q_data.shape[0] #32
seqlen = q_data.shape[1] #200
## qt && (q,a) embedding
q_embed_data = self.q_embed(q_data)
qa_embed_data = self.qa_embed(qa_data)
## copy mk batch times for dkvmn
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data)
self.mem.init_value_memory(memory_value)
## slice data for seqlen times by axis 1
# torch.chunk(tensor, chunk_num, dim)
slice_q_data = torch.chunk(q_data, seqlen, 1)
slice_q_embed_data = torch.chunk(q_embed_data, seqlen, 1)
slice_qa_embed_data = torch.chunk(qa_embed_data, seqlen, 1)
value_read_content_l = []
input_embed_l = []
for i in range(seqlen):
## Attention
q = slice_q_embed_data[i].squeeze(1)
correlation_weight = self.mem.attention(q)
## Read Process
read_content = self.mem.read(correlation_weight)
## save intermedium data
value_read_content_l.append(read_content)
input_embed_l.append(q)
## Write Process
qa = slice_qa_embed_data[i].squeeze(1)
new_memory_value = self.mem.write(correlation_weight, qa)
# Projection
all_read_value_content = torch.cat(
[value_read_content_l[i].unsqueeze(1) for i in range(seqlen)], 1)
input_embed_content = torch.cat(
[input_embed_l[i].unsqueeze(1) for i in range(seqlen)], 1)
## Project rt
input_embed_content = input_embed_content.view(batch_size * seqlen, -1)
input_embed_content = torch.tanh(
self.input_embed_linear(input_embed_content))
input_embed_content = input_embed_content.view(batch_size, seqlen, -1)
## Concat Read_Content and input_embedding_value
predict_input = torch.cat(
[all_read_value_content, input_embed_content], 2)
read_content_embed = torch.tanh(
self.read_embed_linear(predict_input.view(batch_size * seqlen,
-1)))
pred = self.predict_linear(read_content_embed)
# predicts = torch.cat([predict_logs[i] for i in range(seqlen)], 1)
target_1d = target # [batch_size * seq_len, 1]
# mask = target_1d.ge(0) # [batch_size * seq_len, 1]
mask = q_data.gt(0).view(-1, 1)
# pred_1d = predicts.view(-1, 1) # [batch_size * seq_len, 1]
pred_1d = pred.view(-1, 1) # [batch_size * seq_len, 1]
filtered_pred = torch.masked_select(pred_1d, mask)
filtered_target = torch.masked_select(target_1d, mask)
loss = torch.nn.functional.binary_cross_entropy_with_logits(
filtered_pred, filtered_target)
return loss, torch.sigmoid(filtered_pred), filtered_target
def create_model(self):
# 'seq_len' means question sequences
self.q_data = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len],
name='q_data')
self.qa_data = tf.placeholder(
tf.int32, [self.args.batch_size, self.args.seq_len],
name='qa_data')
self.target = tf.placeholder(tf.float32,
[self.args.batch_size, self.args.seq_len],
name='target')
self.kg = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len, 3],
name='knowledge_tag')
self.kg_hot = tf.placeholder(
tf.float32, [self.args.batch_size, self.args.seq_len, 188],
name='knowledge_hot')
self.timebin = tf.placeholder(
tf.int32, [self.args.batch_size, self.args.seq_len])
self.diff = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len])
self.guan = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len])
with tf.variable_scope('Memory'):
init_memory_key = tf.get_variable('key', [self.args.memory_size, self.args.memory_key_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_memory_value = tf.get_variable('value', [self.args.memory_size,self.args.memory_value_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
with tf.variable_scope('time'):
time_embed_mtx = tf.get_variable('timebin', [12, self.args.memory_value_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
with tf.variable_scope('diff'):
guan_embed_mtx = tf.get_variable('diff', [12, self.args.memory_value_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
with tf.variable_scope('gate'):
diff_embed_mtx = tf.get_variable('gate', [12, self.args.memory_value_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_memory_value = tf.tile(tf.expand_dims(init_memory_value, 0),
tf.stack([self.args.batch_size, 1, 1]))
print(init_memory_value.get_shape())
self.memory = DKVMN(self.args.memory_size, self.args.memory_key_state_dim, \
self.args.memory_value_state_dim, init_memory_key=init_memory_key, init_memory_value=init_memory_value, batch_size=self.args.batch_size, name='DKVMN')
with tf.variable_scope('Embedding'):
# A
q_embed_mtx = tf.get_variable('q_embed', [self.args.n_questions+1, self.args.memory_key_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
# B
qa_embed_mtx = tf.get_variable(
'qa_embed', [
2 * self.args.n_questions + 1,
self.args.memory_value_state_dim
],
initializer=tf.truncated_normal_initializer(stddev=0.1))
q_embed_data = tf.nn.embedding_lookup(q_embed_mtx, self.q_data)
slice_q_embed_data = tf.split(q_embed_data, self.args.seq_len, 1)
qa_embed_data = tf.nn.embedding_lookup(qa_embed_mtx, self.qa_data)
slice_qa_embed_data = tf.split(qa_embed_data, self.args.seq_len, 1)
time_embedding = tf.nn.embedding_lookup(time_embed_mtx, self.timebin)
slice_time_embedding = tf.split(time_embedding, self.args.seq_len, 1)
guan_embedding = tf.nn.embedding_lookup(diff_embed_mtx, self.diff)
slice_guan_embedding = tf.split(guan_embedding, self.args.seq_len, 1)
diff_embedding = tf.nn.embedding_lookup(diff_embed_mtx, self.diff)
slice_diff_embedding = tf.split(diff_embedding, self.args.seq_len, 1)
slice_kg = tf.split(self.kg, self.args.seq_len, 1)
slice_kg_hot = tf.split(self.kg_hot, self.args.seq_len, 1)
reuse_flag = False
prediction = list()
# Logics
for i in range(self.args.seq_len):
# To reuse linear vectors
if i != 0:
reuse_flag = True
q = tf.squeeze(slice_q_embed_data[i], 1)
qa = tf.squeeze(slice_qa_embed_data[i], 1)
kg = tf.squeeze(slice_kg[i], 1)
kg_hot = tf.squeeze(slice_kg_hot[i], 1)
dotime = tf.squeeze(slice_time_embedding[i], 1)
dodiff = tf.squeeze(slice_diff_embedding[i], 1)
doguan = tf.squeeze(slice_guan_embedding[i], 1)
self.correlation_weight = self.memory.attention(q, kg, kg_hot)
# # Read process, [batch size, memory value state dim]
self.read_content = self.memory.read(self.correlation_weight)
mastery_level_prior_difficulty = tf.concat(
[self.read_content, q, doguan], 1)
# f_t
summary_vector = tf.tanh(
operations.linear(mastery_level_prior_difficulty,
self.args.final_fc_dim,
name='Summary_Vector',
reuse=reuse_flag))
# p_t
pred_logits = operations.linear(summary_vector,
1,
name='Prediction',
reuse=reuse_flag)
prediction.append(pred_logits)
qa_time = tf.concat([qa, dotime], axis=1)
self.new_memory_value = self.memory.write(self.correlation_weight,
qa_time,
reuse=reuse_flag)
# 'prediction' : seq_len length list of [batch size ,1], make it [batch size, seq_len] tensor
# tf.stack convert to [batch size, seq_len, 1]
self.pred_logits = tf.reshape(tf.stack(
prediction, axis=1), [self.args.batch_size, self.args.seq_len])
# Define loss : standard cross entropy loss, need to ignore '-1' label example
# Make target/label 1-d array
target_1d = tf.reshape(self.target, [-1])
pred_logits_1d = tf.reshape(self.pred_logits, [-1])
index = tf.where(
tf.not_equal(target_1d, tf.constant(-1., dtype=tf.float32)))
# tf.gather(params, indices) : Gather slices from params according to indices
filtered_target = tf.gather(target_1d, index)
filtered_logits = tf.gather(pred_logits_1d, index)
self.loss = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(logits=filtered_logits,
labels=filtered_target))
self.pred = tf.sigmoid(self.pred_logits)
# Optimizer : SGD + MOMENTUM with learning rate decay
self.global_step = tf.Variable(0, trainable=False)
self.lr = tf.placeholder(tf.float32, [], name='learning_rate')
optimizer = tf.train.MomentumOptimizer(self.lr, self.args.momentum)
grads, vrbs = zip(*optimizer.compute_gradients(self.loss))
grad, _ = tf.clip_by_global_norm(grads, self.args.maxgradnorm)
self.train_op = optimizer.apply_gradients(zip(grad, vrbs),
global_step=self.global_step)
self.tr_vrbs = tf.trainable_variables()
self.params = {}
for i in self.tr_vrbs:
print(i.name)
self.params[i.name] = tf.get_default_graph().get_tensor_by_name(
i.name)
self.saver = tf.train.Saver()
class Model():
def __init__(self, args, sess, name='KT'):
self.args = args
self.name = name
self.sess = sess
self.sess.run(tf.global_variables_initializer())
self.create_model()
# if self.load():
# print('CKPT Loaded')
# else:
# raise Exception('CKPT need')
def create_model(self):
# 'seq_len' means question sequences
self.q_data = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len],
name='q_data')
self.qa_data = tf.placeholder(
tf.int32, [self.args.batch_size, self.args.seq_len],
name='qa_data')
self.target = tf.placeholder(tf.float32,
[self.args.batch_size, self.args.seq_len],
name='target')
self.kg = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len, 3],
name='knowledge_tag')
self.kg_hot = tf.placeholder(
tf.float32, [self.args.batch_size, self.args.seq_len, 188],
name='knowledge_hot')
self.timebin = tf.placeholder(
tf.int32, [self.args.batch_size, self.args.seq_len])
self.diff = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len])
self.guan = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len])
with tf.variable_scope('Memory'):
init_memory_key = tf.get_variable('key', [self.args.memory_size, self.args.memory_key_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_memory_value = tf.get_variable('value', [self.args.memory_size,self.args.memory_value_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
with tf.variable_scope('time'):
time_embed_mtx = tf.get_variable('timebin', [12, self.args.memory_value_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
with tf.variable_scope('diff'):
guan_embed_mtx = tf.get_variable('diff', [12, self.args.memory_value_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
with tf.variable_scope('gate'):
diff_embed_mtx = tf.get_variable('gate', [12, self.args.memory_value_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_memory_value = tf.tile(tf.expand_dims(init_memory_value, 0),
tf.stack([self.args.batch_size, 1, 1]))
print(init_memory_value.get_shape())
self.memory = DKVMN(self.args.memory_size, self.args.memory_key_state_dim, \
self.args.memory_value_state_dim, init_memory_key=init_memory_key, init_memory_value=init_memory_value, batch_size=self.args.batch_size, name='DKVMN')
with tf.variable_scope('Embedding'):
# A
q_embed_mtx = tf.get_variable('q_embed', [self.args.n_questions+1, self.args.memory_key_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
# B
qa_embed_mtx = tf.get_variable(
'qa_embed', [
2 * self.args.n_questions + 1,
self.args.memory_value_state_dim
],
initializer=tf.truncated_normal_initializer(stddev=0.1))
q_embed_data = tf.nn.embedding_lookup(q_embed_mtx, self.q_data)
slice_q_embed_data = tf.split(q_embed_data, self.args.seq_len, 1)
qa_embed_data = tf.nn.embedding_lookup(qa_embed_mtx, self.qa_data)
slice_qa_embed_data = tf.split(qa_embed_data, self.args.seq_len, 1)
time_embedding = tf.nn.embedding_lookup(time_embed_mtx, self.timebin)
slice_time_embedding = tf.split(time_embedding, self.args.seq_len, 1)
guan_embedding = tf.nn.embedding_lookup(diff_embed_mtx, self.diff)
slice_guan_embedding = tf.split(guan_embedding, self.args.seq_len, 1)
diff_embedding = tf.nn.embedding_lookup(diff_embed_mtx, self.diff)
slice_diff_embedding = tf.split(diff_embedding, self.args.seq_len, 1)
slice_kg = tf.split(self.kg, self.args.seq_len, 1)
slice_kg_hot = tf.split(self.kg_hot, self.args.seq_len, 1)
reuse_flag = False
prediction = list()
# Logics
for i in range(self.args.seq_len):
# To reuse linear vectors
if i != 0:
reuse_flag = True
q = tf.squeeze(slice_q_embed_data[i], 1)
qa = tf.squeeze(slice_qa_embed_data[i], 1)
kg = tf.squeeze(slice_kg[i], 1)
kg_hot = tf.squeeze(slice_kg_hot[i], 1)
dotime = tf.squeeze(slice_time_embedding[i], 1)
dodiff = tf.squeeze(slice_diff_embedding[i], 1)
doguan = tf.squeeze(slice_guan_embedding[i], 1)
self.correlation_weight = self.memory.attention(q, kg, kg_hot)
# # Read process, [batch size, memory value state dim]
self.read_content = self.memory.read(self.correlation_weight)
mastery_level_prior_difficulty = tf.concat(
[self.read_content, q, doguan], 1)
# f_t
summary_vector = tf.tanh(
operations.linear(mastery_level_prior_difficulty,
self.args.final_fc_dim,
name='Summary_Vector',
reuse=reuse_flag))
# p_t
pred_logits = operations.linear(summary_vector,
1,
name='Prediction',
reuse=reuse_flag)
prediction.append(pred_logits)
qa_time = tf.concat([qa, dotime], axis=1)
self.new_memory_value = self.memory.write(self.correlation_weight,
qa_time,
reuse=reuse_flag)
# 'prediction' : seq_len length list of [batch size ,1], make it [batch size, seq_len] tensor
# tf.stack convert to [batch size, seq_len, 1]
self.pred_logits = tf.reshape(tf.stack(
prediction, axis=1), [self.args.batch_size, self.args.seq_len])
# Define loss : standard cross entropy loss, need to ignore '-1' label example
# Make target/label 1-d array
target_1d = tf.reshape(self.target, [-1])
pred_logits_1d = tf.reshape(self.pred_logits, [-1])
index = tf.where(
tf.not_equal(target_1d, tf.constant(-1., dtype=tf.float32)))
# tf.gather(params, indices) : Gather slices from params according to indices
filtered_target = tf.gather(target_1d, index)
filtered_logits = tf.gather(pred_logits_1d, index)
self.loss = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(logits=filtered_logits,
labels=filtered_target))
self.pred = tf.sigmoid(self.pred_logits)
# Optimizer : SGD + MOMENTUM with learning rate decay
self.global_step = tf.Variable(0, trainable=False)
self.lr = tf.placeholder(tf.float32, [], name='learning_rate')
optimizer = tf.train.MomentumOptimizer(self.lr, self.args.momentum)
grads, vrbs = zip(*optimizer.compute_gradients(self.loss))
grad, _ = tf.clip_by_global_norm(grads, self.args.maxgradnorm)
self.train_op = optimizer.apply_gradients(zip(grad, vrbs),
global_step=self.global_step)
self.tr_vrbs = tf.trainable_variables()
self.params = {}
for i in self.tr_vrbs:
print(i.name)
self.params[i.name] = tf.get_default_graph().get_tensor_by_name(
i.name)
self.saver = tf.train.Saver()
def getParam(self):
"""
Get parameters of DKVMN-CA model
:return:
"""
params = self.sess.run([self.params])
with open('good_future.pkl', 'wb') as f:
pickle.dump(params, f)
def train(self, train_q_data, train_qa_data, valid_q_data, valid_qa_data,
train_kg_data, valid_kg_data, train_kgnum_data, valid_kgnum_data,
traintime, validtime, trainguan, validguan, traindiff,
validdiff):
"""
:param train_q_data: exercises ID
:param train_qa_data: exercises ID and answer result
:param train_kg_data: one-hot form of knowledge concepts
:param train_kgnum_data: knowledge concepts tags
:param traintime: completion time
:param trainguan: the gate of exercise
:param traindiff: the difficulty of exercise
"""
shuffle_index = np.random.permutation(train_q_data.shape[0])
q_data_shuffled = train_q_data[shuffle_index]
qa_data_shuffled = train_qa_data[shuffle_index]
kg_shuffled = train_kgnum_data[shuffle_index]
kghot_shuffled = train_kg_data[shuffle_index]
time_shuffled = traintime[shuffle_index]
guan_shuffled = trainguan[shuffle_index]
diff_shuffled = traindiff[shuffle_index]
training_step = train_q_data.shape[0] // self.args.batch_size
self.sess.run(tf.global_variables_initializer())
self.train_count = 0
if self.args.init_from:
if self.load():
print('Checkpoint_loaded')
else:
print('No checkpoint')
else:
if os.path.exists(
os.path.join(self.args.checkpoint_dir, self.model_dir)):
try:
shutil.rmtree(
os.path.join(self.args.checkpoint_dir, self.model_dir))
shutil.rmtree(
os.path.join(self.args.log_dir,
self.mode_dir + '.csv'))
except (FileNotFoundError, IOError) as e:
print('[Delete Error] %s - %s' % (e.filename, e.strerror))
best_valid_auc = 0
# Training
for epoch in range(0, self.args.num_epochs):
if self.args.show:
bar.next()
pred_list = list()
target_list = list()
epoch_loss = 0
for steps in range(training_step):
# [batch size, seq_len]
q_batch_seq = q_data_shuffled[steps *
self.args.batch_size:(steps +
1) *
self.args.batch_size, :]
qa_batch_seq = qa_data_shuffled[steps *
self.args.batch_size:(steps +
1) *
self.args.batch_size, :]
kg_batch_seq = kg_shuffled[steps *
self.args.batch_size:(steps + 1) *
self.args.batch_size, :]
kghot_batch_seq = kghot_shuffled[steps *
self.args.batch_size:(steps +
1) *
self.args.batch_size, :]
time_batch_seq = time_shuffled[steps *
self.args.batch_size:(steps +
1) *
self.args.batch_size, :]
guan_batch_seq = guan_shuffled[steps *
self.args.batch_size:(steps +
1) *
self.args.batch_size, :]
diff_batch_seq = diff_shuffled[steps *
self.args.batch_size:(steps +
1) *
self.args.batch_size, :]
# qa : exercise index + answer(0 or 1)*exercies_number
# right : 1, wrong : 0, padding : -1
target = qa_batch_seq[:, :]
# Make integer type to calculate target
target = target.astype(np.int)
target_batch = (target - 1) // self.args.n_questions
target_batch = target_batch.astype(np.float)
feed_dict = {
self.kg: kg_batch_seq,
self.q_data: q_batch_seq,
self.qa_data: qa_batch_seq,
self.target: target_batch,
self.kg_hot: kghot_batch_seq,
self.lr: self.args.initial_lr,
self.timebin: time_batch_seq,
self.diff: diff_batch_seq,
self.guan: guan_batch_seq
}
loss_, pred_, _, = self.sess.run(
[self.loss, self.pred, self.train_op], feed_dict=feed_dict)
right_target = np.asarray(target_batch).reshape(-1, 1)
right_pred = np.asarray(pred_).reshape(-1, 1)
right_index = np.flatnonzero(right_target != -1.).tolist()
pred_list.append(right_pred[right_index])
target_list.append(right_target[right_index])
epoch_loss += loss_
if self.args.show:
bar.finish()
all_pred = np.concatenate(pred_list, axis=0)
all_target = np.concatenate(target_list, axis=0)
# Compute metrics
self.auc = metrics.roc_auc_score(all_target, all_pred)
# Extract elements with boolean index
# Make '1' for elements higher than 0.5
# Make '0' for elements lower than 0.5
all_pred[all_pred > 0.5] = 1
all_pred[all_pred <= 0.5] = 0
self.accuracy = metrics.accuracy_score(all_target, all_pred)
epoch_loss = epoch_loss / training_step
print('Epoch %d/%d, loss : %3.5f, auc : %3.5f, accuracy : %3.5f' %
(epoch + 1, self.args.num_epochs, epoch_loss, self.auc,
self.accuracy))
self.write_log(epoch=epoch + 1,
auc=self.auc,
accuracy=self.accuracy,
loss=epoch_loss,
name='training_')
valid_steps = valid_q_data.shape[0] // self.args.batch_size
valid_pred_list = list()
valid_target_list = list()
for s in range(valid_steps):
# Validation
valid_q = valid_q_data[s * self.args.batch_size:(s + 1) *
self.args.batch_size, :]
valid_qa = valid_qa_data[s * self.args.batch_size:(s + 1) *
self.args.batch_size, :]
valid_kg = valid_kgnum_data[s * self.args.batch_size:(s + 1) *
self.args.batch_size, :]
valid_hot_kg = valid_kg_data[s * self.args.batch_size:(s + 1) *
self.args.batch_size, :]
valid_time = validtime[s * self.args.batch_size:(s + 1) *
self.args.batch_size, :]
valid_guan = validguan[s * self.args.batch_size:(s + 1) *
self.args.batch_size, :]
valid_diff = validdiff[s * self.args.batch_size:(s + 1) *
self.args.batch_size, :]
# right : 1, wrong : 0, padding : -1
valid_target = (valid_qa - 1) // self.args.n_questions
valid_feed_dict = {
self.kg: valid_kg,
self.q_data: valid_q,
self.qa_data: valid_qa,
self.kg_hot: valid_hot_kg,
self.target: valid_target,
self.timebin: valid_time,
self.guan: valid_guan,
self.diff: valid_diff
}
valid_loss, valid_pred = self.sess.run(
[self.loss, self.pred], feed_dict=valid_feed_dict)
# Same with training set
valid_right_target = np.asarray(valid_target).reshape(-1, )
valid_right_pred = np.asarray(valid_pred).reshape(-1, )
valid_right_index = np.flatnonzero(
valid_right_target != -1).tolist()
valid_target_list.append(valid_right_target[valid_right_index])
valid_pred_list.append(valid_right_pred[valid_right_index])
all_valid_pred = np.concatenate(valid_pred_list, axis=0)
all_valid_target = np.concatenate(valid_target_list, axis=0)
valid_auc = metrics.roc_auc_score(all_valid_target, all_valid_pred)
# For validation accuracy
stop = 0
all_valid_pred[all_valid_pred > 0.5] = 1
all_valid_pred[all_valid_pred <= 0.5] = 0
valid_accuracy = metrics.accuracy_score(all_valid_target,
all_valid_pred)
print('Epoch %d/%d, valid auc : %3.5f, valid accuracy : %3.5f' %
(epoch + 1, self.args.num_epochs, valid_auc, valid_accuracy))
# Valid log
self.write_log(epoch=epoch + 1,
auc=valid_auc,
accuracy=valid_accuracy,
loss=valid_loss,
name='valid_')
if valid_auc > best_valid_auc:
print('%3.4f to %3.4f' % (best_valid_auc, valid_auc))
best_valid_auc = valid_auc
best_acc = valid_accuracy
best_epoch = epoch + 1
# self.save(best_epoch)
else:
if epoch - best_epoch >= 2:
with open(self.args.dataset + 'concat', 'a') as f:
f.write('auc:' + str(best_valid_auc) + ',acc:' +
str(best_acc) + '\n')
self.args.count += 1
break
@property
def model_dir(self):
return '{}_{}batch_{}epochs'.format(
self.args.dataset + str(self.args.count), self.args.batch_size,
self.args.num_epochs)
def load(self):
checkpoint_dir = os.path.join(self.args.checkpoint_dir, self.model_dir)
ckpt = tf.train.get_checkpoint_state(checkpoint_dir)
if ckpt and ckpt.model_checkpoint_path:
ckpt_name = os.path.basename(ckpt.model_checkpoint_path)
self.train_count = int(ckpt_name.split('-')[-1])
self.saver.restore(self.sess,
os.path.join(checkpoint_dir, ckpt_name))
return True
else:
return False
def save(self, global_step):
model_name = 'DKVMN'
checkpoint_dir = os.path.join(self.args.checkpoint_dir, self.model_dir)
if not os.path.exists(checkpoint_dir):
os.mkdir(checkpoint_dir)
self.saver.save(self.sess,
os.path.join(checkpoint_dir, model_name),
global_step=global_step)
print('Save checkpoint at %d' % (global_step + 1))
# Log file
def write_log(self, auc, accuracy, loss, epoch, name='training_'):
log_path = os.path.join(self.args.log_dir,
name + self.model_dir + '.csv')
if not os.path.exists(log_path):
self.log_file = open(log_path, 'w')
self.log_file.write('Epoch\tAuc\tAccuracy\tloss\n')
else:
self.log_file = open(log_path, 'a')
self.log_file.write(
str(epoch) + '\t' + str(auc) + '\t' + str(accuracy) + '\t' +
str(loss) + '\n')
self.log_file.flush()
def sym_gen(self):
### TODO input variable 'q_data'
q_data = mx.sym.Variable('q_data', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### TODO input variable 'qa_data'
qa_data = mx.sym.Variable('qa_data', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### TODO input variable 'target'
target = mx.sym.Variable('target', shape=(self.seqlen, self.batch_size)) #(seqlen, batch_size)
### Initialize Memory
init_memory_key = mx.sym.Variable('init_memory_key_weight')
init_memory_value = mx.sym.Variable('init_memory_value',
shape=(self.memory_size, self.memory_value_state_dim),
init=mx.init.Normal(0.1)) # (self.memory_size, self.memory_value_state_dim)
init_memory_value = mx.sym.broadcast_to(mx.sym.expand_dims(init_memory_value, axis=0),
shape=(self.batch_size, self.memory_size, self.memory_value_state_dim))
mem = DKVMN(memory_size=self.memory_size,
memory_key_state_dim=self.memory_key_state_dim,
memory_value_state_dim=self.memory_value_state_dim,
init_memory_key=init_memory_key,
init_memory_value=init_memory_value,
name="DKVMN")
### embedding
q_data = mx.sym.BlockGrad(q_data)
q_embed_data = mx.sym.Embedding(data=q_data, input_dim=self.n_question+1,
output_dim=self.q_embed_dim, name='q_embed')
slice_q_embed_data = mx.sym.SliceChannel(q_embed_data, num_outputs=self.seqlen, axis=0, squeeze_axis=True)
qa_data = mx.sym.BlockGrad(qa_data)
qa_embed_data = mx.sym.Embedding(data=qa_data, input_dim=self.n_question*2+1,
output_dim=self.qa_embed_dim, name='qa_embed')
slice_qa_embed_data = mx.sym.SliceChannel(qa_embed_data, num_outputs=self.seqlen, axis=0, squeeze_axis=True)
value_read_content_l = []
input_embed_l = []
readDict = {object :[]}
for i in range(self.seqlen):
## Attention
q = mx.sym.L2Normalization(slice_q_embed_data[i], mode='instance')
correlation_weight = mem.attention(q)
## Read Process
read_content = mem.read(correlation_weight) #Shape (batch_size, memory_state_dim)
### save intermedium data [OLD]
value_read_content_l.append(read_content)
input_embed_l.append(q)
## Write Process
#qa = slice_qa_embed_data[i]
#new_memory_value = mem.write(correlation_weight, mx.sym.Concat(qa , read_content))
qa = mx.sym.concat(mx.sym.L2Normalization(read_content, mode='instance'),mx.sym.L2Normalization(slice_qa_embed_data[i], mode='instance'))
#qa=mx.sym.L2Normalization(slice_qa_embed_data[i], mode='instance')
new_memory_value = mem.write(correlation_weight,qa)
#================================[ Cluster related read_contents based on fuzzy representation] ==============
for i in range(0,len(value_read_content_l)):
current_fuzz_rep = mx.symbol.Custom(data=value_read_content_l[i], name='fuzzkey', op_type='fuzzify')
related = [value_read_content_l[i]]
for j in range(0,len(value_read_content_l)):
if i != j:
tmp_fuzz = mx.symbol.Custom(data=value_read_content_l[j], name='fuzzkey', op_type='fuzzify')
if current_fuzz_rep.tojson() == tmp_fuzz.tojson():
related.append(value_read_content_l[j])
value_read_content_l[i] = mx.sym.Reshape(data=mx.sym.RNN(data=related,state_size=self.memory_value_state_dim,num_layers=2,mode ='lstm',p =0.2), # Shape (batch_size, 1, memory_state_dim)
shape=(-1,self.memory_value_state_dim))
#=================================================================================
all_read_value_content = mx.sym.Concat(*value_read_content_l, num_args=self.seqlen, dim=0)
input_embed_content = mx.sym.Concat(*input_embed_l, num_args=self.seqlen, dim=0)
input_embed_content = mx.sym.FullyConnected(data=mx.sym.L2Normalization(input_embed_content, mode='instance'), num_hidden=64, name="input_embed_content")
input_embed_content = mx.sym.Activation(data=mx.sym.L2Normalization(input_embed_content, mode='instance'), act_type='tanh', name="input_embed_content_tanh")
read_content_embed = mx.sym.FullyConnected(data=mx.sym.Concat(mx.sym.L2Normalization(all_read_value_content, mode='instance'), mx.sym.L2Normalization(input_embed_content, mode='instance'), num_args=2, dim=1),
num_hidden=self.final_fc_dim, name="read_content_embed")
read_content_embed = mx.sym.Activation(data= mx.sym.L2Normalization(read_content_embed, mode='instance'), act_type='tanh', name="read_content_embed_tanh")
#================================================[ Updated for F value]====================================
# for i in range(self.seqlen):
# ## Write Process
# qa = mx.symbol.batch_dot(slice_qa_embed_data[i],read_content_embed)
# #qa = mx.sym.Concat(slice_qa_embed_data[i],read_content_embed)
# #qa = read_content_embed
# new_memory_value = mem.write(correlation_weight, qa)
#==========================================================================================================
pred = mx.sym.FullyConnected(data=mx.sym.L2Normalization(read_content_embed, mode='instance'), num_hidden=1, name="final_fc")
pred_prob = logistic_regression_mask_output(data=mx.sym.Reshape(pred, shape=(-1, )),
label=mx.sym.Reshape(data=target, shape=(-1,)),
ignore_label=-1., name='final_pred')
return mx.sym.Group([pred_prob])
class MODEL(nn.Module):
def __init__(self,
n_question,
batch_size,
q_embed_dim,
qa_embed_dim,
memory_size,
memory_key_state_dim,
memory_value_state_dim,
final_fc_dim,
student_num=None):
self.n_question = n_question
self.batch_size = batch_size
self.q_embed_dim = q_embed_dim
self.qa_embed_dim = qa_embed_dim
self.memory_size = memory_size
self.memory_key_state_dim = memory_key_state_dim
self.memory_value_state_dim = memory_value_state_dim
self.final_fc_dim = final_fc_dim
self.student_num = student_num
self.input_embed_linear = nn.Linear(self.q_embed_dim,
self.final_fc_dim,
bias=True)
self.read_embed_linear = nn.Linear(self.memory_value_state_dim +
self.final_fc_dim,
self.final_fc_dim,
bias=True)
self.predict_linear = nn.Linear(self.final_fc_dim, 1, bias=True)
self.init_memory_key = nn.Parameter(
torch.randn(self.memory_size, self.memory_key_state_dim))
nn.init.kaiming_normal(self.init_memory_key)
self.init_memory_value = nn.Parameter(
torch.randn(self.memory_size, self.memory_value_state_dim))
nn.init.kaiming_normal(self.init_memory_value)
self.mem = DKVMN(self.memory_size, self.memory_key_state_dim,
self.memory_value_state_dim, self.init_memory_key)
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data)
self.mem.set_memory_value(memory_value)
self.q_embed = nn.Embedding(self.n_question + 1,
self.q_embed_dim,
padding_idx=0)
self.qa_embed = nn.Embedding(self.n_question * 2 + 1,
self.qa_embed_dim,
padding_idx=0)
def init_params(self):
nn.init.kaiming_normal(self.predict_linear.weight)
nn.init.kaiming_normal(self.read_embed_linear.weight)
nn.init.constant(self.read_embed_linear.bias, 0)
nn.init.constant(self.predict_linear.bias, 0)
def init_embeddings(self):
nn.init.kaiming_normal(self.q_embed.weight)
nn.init.kaiming_normal(self.qa_embed.weight)
def forward(self, q_data, qa_data, target, student_id=None):
batch_size = q_data.shpae[0]
seqlen = q_data.shape[1]
q_embed_data = self.q_embed(q_data)
qa_embed_data = self.qa_embed(qa_data)
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data)
self.mem.set_memory_value(memory_value)
slice_q_data = torch.chunk(q_data, seqlen, 1)
slice_q_embed_data = torch.chunk(q_embed_data, seqlen, 1)
slice_qa_embed_data = torch.chunk(qa_embed_data, seqlen, 1)
value_read_content_1 = []
input_embed_1 = []
predict_logs = []
for i in range(seqlen):
# attention
q = slice_q_embed_data[i].squeeze(1)
correlation_weight = self.mem.attention(q)
if_memory_write = slice_q_data[i].squeeze(1).ge(1)
if_memory_write = utils.variable(
torch.FloatTensor(if_memory_write.data.tolist()), 1)
# read
read_content = self.mem.read(correlation_weight)
value_read_content_1.append(read_content)
input_embed_1.append(q)
# write
qa = slice_qa_embed_data[i].squeeze(1)
new_memory_value = self.mem.write(correlation_weight, qa)
all_read_value_content = torch.cat(
[value_read_content_1[i].squeeze(1) for i in range(seqlen)], 1)
input_embed_content = torch.cat(
[input_embed_1[i].squeeze(1) for i in range(seqlen)], 1)
predict_input = torch.cat(
[all_read_value_content, input_embed_content], 2)
read_content_embed = torch.tanh(
self.read_embed_linear(
predict_input.reshape(batch_size * seqlen, -1)))
pred = self.predict_linear(read_content_embed)
target_1d = target
mask = target_1d.ge(0)
pred_1d = pred.reshape(-1, 1)
filtered_pred = torch.masked_select(pred_1d, mask)
filtered_target = torch.masked_select(target_1d, mask)
loss = nn.functional.binary_cross_entropy_with_logits(
filtered_pred, filtered_target)
return loss, torch.sigmoid(filtered_pred), filtered_target
def sym_gen(self):
### TODO input variable 'q_data'
q_data = mx.sym.Variable('q_data', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### TODO input variable 'qa_data'
qa_data = mx.sym.Variable('qa_data', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### TODO input variable 'target'
target = mx.sym.Variable('target', shape=(self.seqlen, self.batch_size)) #(seqlen, batch_size)
### Initialize Memory
init_memory_key = mx.sym.Variable('init_memory_key_weight')
init_memory_value = mx.sym.Variable('init_memory_value',
shape=(self.memory_size, self.memory_value_state_dim),
init=mx.init.Normal(0.1)) # (self.memory_size, self.memory_value_state_dim)
init_memory_value = mx.sym.broadcast_to(mx.sym.expand_dims(init_memory_value, axis=0),
shape=(self.batch_size, self.memory_size, self.memory_value_state_dim))
mem = DKVMN(memory_size=self.memory_size,
memory_key_state_dim=self.memory_key_state_dim,
memory_value_state_dim=self.memory_value_state_dim,
init_memory_key=init_memory_key,
init_memory_value=init_memory_value,
name="DKVMN")
### embedding
q_data = mx.sym.BlockGrad(q_data)
q_embed_data = mx.sym.Embedding(data=q_data, input_dim=self.n_question+1,
output_dim=self.q_embed_dim, name='q_embed')
slice_q_embed_data = mx.sym.SliceChannel(q_embed_data, num_outputs=self.seqlen, axis=0, squeeze_axis=True)
qa_data = mx.sym.BlockGrad(qa_data)
qa_embed_data = mx.sym.Embedding(data=qa_data, input_dim=self.n_question*2+1,
output_dim=self.qa_embed_dim, name='qa_embed')
slice_qa_embed_data = mx.sym.SliceChannel(qa_embed_data, num_outputs=self.seqlen, axis=0, squeeze_axis=True)
value_read_content_l = []
input_embed_l = []
for i in range(self.seqlen):
## Attention
q = slice_q_embed_data[i]
correlation_weight = mem.attention(q)
## Read Process
read_content = mem.read(correlation_weight) #Shape (batch_size, memory_state_dim)
### save intermedium data
value_read_content_l.append(read_content)
input_embed_l.append(q)
## Write Process
qa = slice_qa_embed_data[i]
new_memory_value = mem.write(correlation_weight, qa)
all_read_value_content = mx.sym.Concat(*value_read_content_l, num_args=self.seqlen, dim=0)
input_embed_content = mx.sym.Concat(*input_embed_l, num_args=self.seqlen, dim=0)
input_embed_content = mx.sym.FullyConnected(data=input_embed_content, num_hidden=50, name="input_embed_content")
input_embed_content = mx.sym.Activation(data=input_embed_content, act_type='tanh', name="input_embed_content_tanh")
read_content_embed = mx.sym.FullyConnected(data=mx.sym.Concat(all_read_value_content, input_embed_content, num_args=2, dim=1),
num_hidden=self.final_fc_dim, name="read_content_embed")
read_content_embed = mx.sym.Activation(data=read_content_embed, act_type='tanh', name="read_content_embed_tanh")
pred = mx.sym.FullyConnected(data=read_content_embed, num_hidden=1, name="final_fc")
pred_prob = logistic_regression_mask_output(data=mx.sym.Reshape(pred, shape=(-1, )),
label=mx.sym.Reshape(data=target, shape=(-1,)),
ignore_label=-1., name='final_pred')
return mx.sym.Group([pred_prob, pred, read_content_embed,correlation_weight])
def create_model(self):
# 'seq_len' means question sequences
self.q_data = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len],
name='q_data')
self.qa_data = tf.placeholder(
tf.int32, [self.args.batch_size, self.args.seq_len],
name='qa_data')
self.target = tf.placeholder(tf.float32,
[self.args.batch_size, self.args.seq_len],
name='target')
# Initialize Memory
with tf.variable_scope('Memory'):
init_memory_key = tf.get_variable('key', [self.args.memory_size, self.args.memory_key_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_memory_value = tf.get_variable('value', [self.args.memory_size,self.args.memory_value_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Broadcast memory value tensor to match [batch size, memory size, memory state dim]
# First expand dim at axis 0 so that makes 'batch size' axis and tile it along 'batch size' axis
# tf.tile(inputs, multiples) : multiples length must be thes saame as the number of dimensions in input
# tf.stack takes a list and convert each element to a tensor
init_memory_value = tf.tile(tf.expand_dims(init_memory_value, 0),
tf.stack([self.args.batch_size, 1, 1]))
print(init_memory_value.get_shape())
self.memory = DKVMN(self.args.memory_size, self.args.memory_key_state_dim, \
self.args.memory_value_state_dim, init_memory_key=init_memory_key, init_memory_value=init_memory_value, name='DKVMN')
# Embedding to [batch size, seq_len, memory_state_dim(d_k or d_v)]
with tf.variable_scope('Embedding'):
# A
q_embed_mtx = tf.get_variable('q_embed', [self.args.n_questions+1, self.args.memory_key_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
# B
qa_embed_mtx = tf.get_variable(
'qa_embed', [
2 * self.args.n_questions + 1,
self.args.memory_value_state_dim
],
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Embedding to [batch size, seq_len, memory key state dim]
q_embed_data = tf.nn.embedding_lookup(q_embed_mtx, self.q_data)
# List of [batch size, 1, memory key state dim] with 'seq_len' elements
#print('Q_embedding shape : %s' % q_embed_data.get_shape())
slice_q_embed_data = tf.split(q_embed_data, self.args.seq_len, 1)
#print(len(slice_q_embed_data), type(slice_q_embed_data), slice_q_embed_data[0].get_shape())
# Embedding to [batch size, seq_len, memory value state dim]
qa_embed_data = tf.nn.embedding_lookup(qa_embed_mtx, self.qa_data)
#print('QA_embedding shape: %s' % qa_embed_data.get_shape())
# List of [batch size, 1, memory value state dim] with 'seq_len' elements
slice_qa_embed_data = tf.split(qa_embed_data, self.args.seq_len, 1)
prediction = list()
reuse_flag = False
# Logics
for i in range(self.args.seq_len):
# To reuse linear vectors
if i != 0:
reuse_flag = True
# k_t : [batch size, memory key state dim]
q = tf.squeeze(slice_q_embed_data[i], 1)
# Attention, [batch size, memory size]
self.correlation_weight = self.memory.attention(q)
# Read process, [batch size, memory value state dim]
self.read_content = self.memory.read(self.correlation_weight)
# Write process, [batch size, memory size, memory value state dim]
# qa : [batch size, memory value state dim]
qa = tf.squeeze(slice_qa_embed_data[i], 1)
# Only last time step value is necessary
self.new_memory_value = self.memory.write(self.correlation_weight,
qa,
reuse=reuse_flag)
mastery_level_prior_difficulty = tf.concat([self.read_content, q],
1)
# f_t
summary_vector = tf.tanh(
operations.linear(mastery_level_prior_difficulty,
self.args.final_fc_dim,
name='Summary_Vector',
reuse=reuse_flag))
# p_t
pred_logits = operations.linear(summary_vector,
1,
name='Prediction',
reuse=reuse_flag)
prediction.append(pred_logits)
# 'prediction' : seq_len length list of [batch size ,1], make it [batch size, seq_len] tensor
# tf.stack convert to [batch size, seq_len, 1]
self.pred_logits = tf.reshape(tf.stack(
prediction, axis=1), [self.args.batch_size, self.args.seq_len])
# Define loss : standard cross entropy loss, need to ignore '-1' label example
# Make target/label 1-d array
target_1d = tf.reshape(self.target, [-1])
pred_logits_1d = tf.reshape(self.pred_logits, [-1])
index = tf.where(
tf.not_equal(target_1d, tf.constant(-1., dtype=tf.float32)))
# tf.gather(params, indices) : Gather slices from params according to indices
filtered_target = tf.gather(target_1d, index)
filtered_logits = tf.gather(pred_logits_1d, index)
self.loss = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(logits=filtered_logits,
labels=filtered_target))
self.pred = tf.sigmoid(self.pred_logits)
# Optimizer : SGD + MOMENTUM with learning rate decay
self.global_step = tf.Variable(0, trainable=False)
self.lr = tf.placeholder(tf.float32, [], name='learning_rate')
# self.lr_decay = tf.train.exponential_decay(self.args.initial_lr, global_step=global_step, decay_steps=10000, decay_rate=0.667, staircase=True)
# self.learning_rate = tf.maximum(lr, self.args.lr_lowerbound)
optimizer = tf.train.MomentumOptimizer(self.lr, self.args.momentum)
grads, vrbs = zip(*optimizer.compute_gradients(self.loss))
grad, _ = tf.clip_by_global_norm(grads, self.args.maxgradnorm)
self.train_op = optimizer.apply_gradients(zip(grad, vrbs),
global_step=self.global_step)
# grad_clip = [(tf.clip_by_value(grad, -self.args.maxgradnorm, self.args.maxgradnorm), var) for grad, var in grads]
self.tr_vrbs = tf.trainable_variables()
for i in self.tr_vrbs:
print(i.name)
self.saver = tf.train.Saver()
def sym_gen(self):
### TODO input variable 'q_data'
q_data = mx.sym.Variable('q_data', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### TODO input variable 'qa_data'
qa_data = mx.sym.Variable('qa_data', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### TODO input variable 'target'
target = mx.sym.Variable('target', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### Initialize Memory
init_memory_key = mx.sym.Variable('init_memory_key_weight')
init_memory_value = mx.sym.Variable('init_memory_value',
shape=(self.memory_size, self.memory_value_state_dim),
init=mx.init.Normal(0.1)) # (self.memory_size, self.memory_value_state_dim)
init_memory_value = mx.sym.broadcast_to(mx.sym.expand_dims(init_memory_value, axis=0),
shape=(self.batch_size, self.memory_size, self.memory_value_state_dim))
mem = DKVMN(memory_size=self.memory_size,
memory_key_state_dim=self.memory_key_state_dim,
memory_value_state_dim=self.memory_value_state_dim,
init_memory_key=init_memory_key,
init_memory_value=init_memory_value,
name="DKVMN")
### embedding
q_data = mx.sym.BlockGrad(q_data)
q_embed_data = mx.sym.Embedding(data=q_data, input_dim=self.n_question + 1,
output_dim=self.q_embed_dim, name='q_embed')
slice_q_embed_data = mx.sym.SliceChannel(q_embed_data, num_outputs=self.seqlen, axis=0, squeeze_axis=True)
qa_data = mx.sym.BlockGrad(qa_data)
qa_embed_data = mx.sym.Embedding(data=qa_data, input_dim=self.n_question * 2 + 1,
output_dim=self.qa_embed_dim, name='qa_embed')
slice_qa_embed_data = mx.sym.SliceChannel(qa_embed_data, num_outputs=self.seqlen, axis=0, squeeze_axis=True)
# memory block
value_read_content_l = [] # (seqlen, batch_size, memory_state_dim)
input_embed_l = [] # (seqlen, batch_size, q_embed_dim)
for i in range(self.seqlen):
## Attention
q = slice_q_embed_data[i]
correlation_weight = mem.attention(q)
## Read Process
read_content = mem.read(correlation_weight) # Shape (batch_size, memory_state_dim)
### save intermedium data
value_read_content_l.append(read_content)
input_embed_l.append(q)
## Write Process
qa = slice_qa_embed_data[i]
new_memory_value = mem.write(correlation_weight, qa)
# (batch_size * seqlen, memory_state_dim)
all_read_value_content = mx.sym.Concat(*value_read_content_l, num_args=self.seqlen, dim=0)
all_read_value_content = mx.sym.reshape(data=all_read_value_content, shape=(self.seqlen, self.batch_size, -1))
# (batch_size * seqlen, q_embed_dim)
input_embed_content = mx.sym.Concat(*input_embed_l, num_args=self.seqlen, dim=0)
input_embed_content = mx.sym.reshape(data=input_embed_content, shape=(self.seqlen, self.batch_size, -1))
combined_data = mx.sym.Concat(all_read_value_content, input_embed_content, num_args=2, dim=2)
lstm = mx.gluon.rnn.LSTM(50, num_layers=1, layout='TNC', prefix='LSTM')
# (seqlen, batch_size, final_fc_dim)
output = lstm(combined_data)
output = mx.sym.reshape(data=output, shape=(-3, 0))
# output = mx.sym.FullyConnected(data=output, num_hidden=self.final_fc_dim, name='fc')
# output = mx.sym.Activation(data=output, act_type='tanh', name='fc_tanh')
pred = mx.sym.FullyConnected(data=output, num_hidden=1, name="final_fc")
pred_prob = logistic_regression_mask_output(data=mx.sym.Reshape(pred, shape=(-1,)),
label=mx.sym.Reshape(data=target, shape=(-1,)),
ignore_label=-1., name='final_pred')
mx.sym.softmax_cross_entropy()
net = mx.sym.Group([pred_prob])
return net
class MODEL(nn.Module):
def __init__(self,
n_question,
batch_size,
q_embed_dim,
qa_embed_dim,
memory_size,
memory_key_state_dim,
memory_value_state_dim,
final_fc_dim,
student_num=None):
super(MODEL, self).__init__()
self.n_question = n_question
self.batch_size = batch_size
self.q_embed_dim = q_embed_dim
self.qa_embed_dim = qa_embed_dim
self.memory_size = memory_size
self.memory_key_state_dim = memory_key_state_dim
self.memory_value_state_dim = memory_value_state_dim
self.final_fc_dim = final_fc_dim
self.student_num = student_num
self.input_embed_linear = nn.Linear(self.q_embed_dim,
self.final_fc_dim,
bias=True)
self.read_embed_linear = nn.Linear(self.memory_value_state_dim +
self.final_fc_dim,
self.final_fc_dim,
bias=True)
self.predict_linear = nn.Linear(self.final_fc_dim, 1, bias=True)
self.init_memory_key = nn.Parameter(
torch.randn(self.memory_size, self.memory_key_state_dim)) # random
nn.init.kaiming_normal_(self.init_memory_key)
self.init_memory_value = nn.Parameter(
torch.randn(self.memory_size, self.memory_value_state_dim)) #
nn.init.kaiming_normal_(self.init_memory_value)
self.mem = DKVMN(
memory_size=self.memory_size,
memory_key_state_dim=self.
memory_key_state_dim, # memory_key 初始化后不变化
memory_value_state_dim=self.memory_value_state_dim,
init_memory_key=self.init_memory_key) # 不断 write 更新memo value
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data)
self.mem.init_value_memory(memory_value)
self.q_embed = nn.Embedding(self.n_question + 1,
self.q_embed_dim,
padding_idx=0)
self.qa_embed = nn.Embedding(2 * self.n_question + 1,
self.qa_embed_dim,
padding_idx=0)
def init_params(self):
nn.init.kaiming_normal_(self.predict_linear.weight)
nn.init.kaiming_normal_(self.read_embed_linear.weight)
nn.init.constant_(self.read_embed_linear.bias, 0)
nn.init.constant_(self.predict_linear.bias, 0)
# nn.init.constant_(self.input_embed_linear.bias, 0)
# nn.init.normal(self.input_embed_linear.weight, std=0.02)
def init_embeddings(self):
nn.init.kaiming_normal_(self.q_embed.weight)
nn.init.kaiming_normal_(self.qa_embed.weight)
def forward(self, q_data, qa_data, target, student_id=None):
batch_size = q_data.shape[0]
seqlen = q_data.shape[1]
q_embed_data = self.q_embed(q_data)
qa_embed_data = self.qa_embed(qa_data)
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data) # memory: 32, 20, 200
self.mem.init_value_memory(memory_value)
slice_q_data = torch.chunk(q_data, seqlen, 1)
slice_q_embed_data = torch.chunk(q_embed_data, seqlen, 1)
slice_qa_embed_data = torch.chunk(qa_embed_data, seqlen, 1)
value_read_content_l = []
input_embed_l = []
# new_memory_value_l = []
predict_logs = []
for i in range(seqlen):
## Attention
q = slice_q_embed_data[i].squeeze(1)
correlation_weight = self.mem.attention(q)
if_memory_write = slice_q_data[i].squeeze(1).ge(1) # q
if_memory_write = utils.varible(
torch.FloatTensor(if_memory_write.data.tolist()), 1)
## Read Process
read_content = self.mem.read(correlation_weight)
value_read_content_l.append(read_content)
input_embed_l.append(q)
## Write Process
qa = slice_qa_embed_data[i].squeeze(1)
new_memory_value = self.mem.write(
correlation_weight, qa,
if_memory_write) # 直接把200个seq最后一次更新的memory_value作为知识水平向量输出
# new_memory_value_l.append(new_memory_value.squ)
# read_content_embed = torch.tanh(self.read_embed_linear(torch.cat([read_content, q], 1)))
# pred = self.predict_linear(read_content_embed)
# predict_logs.append(pred)
all_read_value_content = torch.cat(
[value_read_content_l[i].unsqueeze(1) for i in range(seqlen)],
1) # 将每一个习题的内容拼接起来
input_embed_content = torch.cat(
[input_embed_l[i].unsqueeze(1) for i in range(seqlen)], 1)
# input_embed_content = input_embed_content.view(batch_size * seqlen, -1)
# input_embed_content = torch.tanh(self.input_embed_linear(input_embed_content))
# input_embed_content = input_embed_content.view(batch_size, seqlen, -1)
predict_input = torch.cat(
[all_read_value_content, input_embed_content], 2)
read_content_embed = torch.tanh(
self.read_embed_linear(predict_input.view(batch_size * seqlen,
-1)))
pred = self.predict_linear(read_content_embed)
# predicts = torch.cat([predict_logs[i] for i in range(seqlen)], 1)
target_1d = target # [batch_size * seq_len, 1]
mask = target_1d.ge(0) # [batch_size * seq_len, 1]
# pred_1d = predicts.view(-1, 1) # [batch_size * seq_len, 1]
pred_1d = pred.view(-1, 1) # [batch_size * seq_len, 1]
filtered_pred = torch.masked_select(pred_1d, mask)
filtered_target = torch.masked_select(target_1d, mask)
# memory_value = torch.masked_select(new_memory_value.view(batch_size * seqlen, -1), mask)
loss = torch.nn.functional.binary_cross_entropy_with_logits(
filtered_pred, filtered_target)
return loss, torch.sigmoid(
filtered_pred), filtered_target, new_memory_value
def _influence(self):
# Initialize Memory
logger.info("Initializing Key and Value Memory")
with tf.variable_scope("Memory"):
init_key_memory = tf.get_variable(
'key_memory_matrix',
[self.args.memory_size, self.args.key_memory_state_dim],
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_value_memory = tf.get_variable(
'value_memory_matrix',
[self.args.memory_size, self.args.value_memory_state_dim],
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Boardcast value-memory matrix to Shape (batch_size, memory_size, memory_value_state_dim)
init_value_memory = tf.tile( # tile the number of value-memory by the number of batch
tf.expand_dims(init_value_memory, 0), # make the batch-axis
tf.stack([self.args.batch_size, 1, 1]))
logger.debug("Shape of init_value_memory = {}".format(
init_value_memory.get_shape()))
logger.debug("Shape of init_key_memory = {}".format(
init_key_memory.get_shape()))
# Initialize DKVMN
self.memory = DKVMN(
memory_size=self.args.memory_size,
key_memory_state_dim=self.args.key_memory_state_dim,
value_memory_state_dim=self.args.value_memory_state_dim,
init_key_memory=init_key_memory,
init_value_memory=init_value_memory,
name="DKVMN")
# Initialize Embedding
logger.info("Initializing Q and QA Embedding")
with tf.variable_scope('Embedding'):
q_embed_matrix = tf.get_variable(
'q_embed',
[self.args.n_questions + 1, self.args.key_memory_state_dim],
initializer=tf.truncated_normal_initializer(stddev=0.1))
qa_embed_matrix = tf.get_variable(
'qa_embed', [
2 * self.args.n_questions + 1,
self.args.value_memory_state_dim
],
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Embedding to Shape (batch size, seq_len, memory_state_dim(d_k or d_v))
logger.info("Initializing Embedding Lookup")
q_embed_data = tf.nn.embedding_lookup(q_embed_matrix, self.q_data)
qa_embed_data = tf.nn.embedding_lookup(qa_embed_matrix, self.qa_data)
logger.debug("Shape of q_embed_data: {}".format(
q_embed_data.get_shape()))
logger.debug("Shape of qa_embed_data: {}".format(
qa_embed_data.get_shape()))
sliced_q_embed_data = tf.split(value=q_embed_data,
num_or_size_splits=self.args.seq_len,
axis=1)
sliced_qa_embed_data = tf.split(value=qa_embed_data,
num_or_size_splits=self.args.seq_len,
axis=1)
logger.debug("Shape of sliced_q_embed_data[0]: {}".format(
sliced_q_embed_data[0].get_shape()))
logger.debug("Shape of sliced_qa_embed_data[0]: {}".format(
sliced_qa_embed_data[0].get_shape()))
pred_z_values = list()
student_abilities = list()
question_difficulties = list()
reuse_flag = False
logger.info("Initializing Influence Procedure")
for i in range(self.args.seq_len):
# To reuse linear vectors
if i != 0:
reuse_flag = True
# Get the query and content vector
q = tf.squeeze(sliced_q_embed_data[i], 1)
qa = tf.squeeze(sliced_qa_embed_data[i], 1)
logger.debug("qeury vector q: {}".format(q))
logger.debug("content vector qa: {}".format(qa))
# Attention, correlation_weight: Shape (batch_size, memory_size)
self.correlation_weight = self.memory.attention(
embedded_query_vector=q)
logger.debug("correlation_weight: {}".format(
self.correlation_weight))
# Read process, read_content: (batch_size, value_memory_state_dim)
self.read_content = self.memory.read(
correlation_weight=self.correlation_weight)
logger.debug("read_content: {}".format(self.read_content))
# Write process, new_memory_value: Shape (batch_size, memory_size, value_memory_state_dim)
self.new_memory_value = self.memory.write(self.correlation_weight,
qa,
reuse=reuse_flag)
logger.debug("new_memory_value: {}".format(self.new_memory_value))
# Build the feature vector -- summary_vector
mastery_level_prior_difficulty = tf.concat([self.read_content, q],
1)
self.summary_vector = layers.fully_connected(
inputs=mastery_level_prior_difficulty,
num_outputs=self.args.summary_vector_output_dim,
scope='SummaryOperation',
reuse=reuse_flag,
activation_fn=tf.nn.tanh)
logger.debug("summary_vector: {}".format(self.summary_vector))
# Calculate the student ability level from summary vector
student_ability = layers.fully_connected(
inputs=self.summary_vector,
num_outputs=1,
scope='StudentAbilityOutputLayer',
reuse=reuse_flag,
activation_fn=None)
# Calculate the question difficulty level from the question embedding
question_difficulty = layers.fully_connected(
inputs=q,
num_outputs=1,
scope='QuestionDifficultyOutputLayer',
reuse=reuse_flag,
activation_fn=tf.nn.tanh)
# Prediction
pred_z_value = 3.0 * student_ability - question_difficulty
pred_z_values.append(pred_z_value)
student_abilities.append(student_ability)
question_difficulties.append(question_difficulty)
self.pred_z_values = tf.reshape(tf.stack(
pred_z_values, axis=1), [self.args.batch_size, self.args.seq_len])
self.student_abilities = tf.reshape(
tf.stack(student_abilities, axis=1),
[self.args.batch_size, self.args.seq_len])
self.question_difficulties = tf.reshape(
tf.stack(question_difficulties, axis=1),
[self.args.batch_size, self.args.seq_len])
logger.debug("Shape of pred_z_values: {}".format(self.pred_z_values))
logger.debug("Shape of student_abilities: {}".format(
self.student_abilities))
logger.debug("Shape of question_difficulties: {}".format(
self.question_difficulties))
class DeepIRTModel(object):
def __init__(self, args, sess, name="KT"):
self.args = args
self.sess = sess
self.name = name
self.create_model()
def create_model(self):
self._create_placeholder()
self._influence()
self._create_loss()
self._create_optimizer()
self._add_summary()
def _create_placeholder(self):
logger.info("Initializing Placeholder")
self.q_data = tf.placeholder(tf.int32,
[self.args.batch_size, self.args.seq_len],
name='q_data')
self.qa_data = tf.placeholder(
tf.int32, [self.args.batch_size, self.args.seq_len],
name='qa_data')
self.label = tf.placeholder(tf.float32,
[self.args.batch_size, self.args.seq_len],
name='label')
def _influence(self):
# Initialize Memory
logger.info("Initializing Key and Value Memory")
with tf.variable_scope("Memory"):
init_key_memory = tf.get_variable(
'key_memory_matrix',
[self.args.memory_size, self.args.key_memory_state_dim],
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_value_memory = tf.get_variable(
'value_memory_matrix',
[self.args.memory_size, self.args.value_memory_state_dim],
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Boardcast value-memory matrix to Shape (batch_size, memory_size, memory_value_state_dim)
init_value_memory = tf.tile( # tile the number of value-memory by the number of batch
tf.expand_dims(init_value_memory, 0), # make the batch-axis
tf.stack([self.args.batch_size, 1, 1]))
logger.debug("Shape of init_value_memory = {}".format(
init_value_memory.get_shape()))
logger.debug("Shape of init_key_memory = {}".format(
init_key_memory.get_shape()))
# Initialize DKVMN
self.memory = DKVMN(
memory_size=self.args.memory_size,
key_memory_state_dim=self.args.key_memory_state_dim,
value_memory_state_dim=self.args.value_memory_state_dim,
init_key_memory=init_key_memory,
init_value_memory=init_value_memory,
name="DKVMN")
# Initialize Embedding
logger.info("Initializing Q and QA Embedding")
with tf.variable_scope('Embedding'):
q_embed_matrix = tf.get_variable(
'q_embed',
[self.args.n_questions + 1, self.args.key_memory_state_dim],
initializer=tf.truncated_normal_initializer(stddev=0.1))
qa_embed_matrix = tf.get_variable(
'qa_embed', [
2 * self.args.n_questions + 1,
self.args.value_memory_state_dim
],
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Embedding to Shape (batch size, seq_len, memory_state_dim(d_k or d_v))
logger.info("Initializing Embedding Lookup")
q_embed_data = tf.nn.embedding_lookup(q_embed_matrix, self.q_data)
qa_embed_data = tf.nn.embedding_lookup(qa_embed_matrix, self.qa_data)
logger.debug("Shape of q_embed_data: {}".format(
q_embed_data.get_shape()))
logger.debug("Shape of qa_embed_data: {}".format(
qa_embed_data.get_shape()))
sliced_q_embed_data = tf.split(value=q_embed_data,
num_or_size_splits=self.args.seq_len,
axis=1)
sliced_qa_embed_data = tf.split(value=qa_embed_data,
num_or_size_splits=self.args.seq_len,
axis=1)
logger.debug("Shape of sliced_q_embed_data[0]: {}".format(
sliced_q_embed_data[0].get_shape()))
logger.debug("Shape of sliced_qa_embed_data[0]: {}".format(
sliced_qa_embed_data[0].get_shape()))
pred_z_values = list()
student_abilities = list()
question_difficulties = list()
reuse_flag = False
logger.info("Initializing Influence Procedure")
for i in range(self.args.seq_len):
# To reuse linear vectors
if i != 0:
reuse_flag = True
# Get the query and content vector
q = tf.squeeze(sliced_q_embed_data[i], 1)
qa = tf.squeeze(sliced_qa_embed_data[i], 1)
logger.debug("qeury vector q: {}".format(q))
logger.debug("content vector qa: {}".format(qa))
# Attention, correlation_weight: Shape (batch_size, memory_size)
self.correlation_weight = self.memory.attention(
embedded_query_vector=q)
logger.debug("correlation_weight: {}".format(
self.correlation_weight))
# Read process, read_content: (batch_size, value_memory_state_dim)
self.read_content = self.memory.read(
correlation_weight=self.correlation_weight)
logger.debug("read_content: {}".format(self.read_content))
# Write process, new_memory_value: Shape (batch_size, memory_size, value_memory_state_dim)
self.new_memory_value = self.memory.write(self.correlation_weight,
qa,
reuse=reuse_flag)
logger.debug("new_memory_value: {}".format(self.new_memory_value))
# Build the feature vector -- summary_vector
mastery_level_prior_difficulty = tf.concat([self.read_content, q],
1)
self.summary_vector = layers.fully_connected(
inputs=mastery_level_prior_difficulty,
num_outputs=self.args.summary_vector_output_dim,
scope='SummaryOperation',
reuse=reuse_flag,
activation_fn=tf.nn.tanh)
logger.debug("summary_vector: {}".format(self.summary_vector))
# Calculate the student ability level from summary vector
student_ability = layers.fully_connected(
inputs=self.summary_vector,
num_outputs=1,
scope='StudentAbilityOutputLayer',
reuse=reuse_flag,
activation_fn=None)
# Calculate the question difficulty level from the question embedding
question_difficulty = layers.fully_connected(
inputs=q,
num_outputs=1,
scope='QuestionDifficultyOutputLayer',
reuse=reuse_flag,
activation_fn=tf.nn.tanh)
# Prediction
pred_z_value = 3.0 * student_ability - question_difficulty
pred_z_values.append(pred_z_value)
student_abilities.append(student_ability)
question_difficulties.append(question_difficulty)
self.pred_z_values = tf.reshape(tf.stack(
pred_z_values, axis=1), [self.args.batch_size, self.args.seq_len])
self.student_abilities = tf.reshape(
tf.stack(student_abilities, axis=1),
[self.args.batch_size, self.args.seq_len])
self.question_difficulties = tf.reshape(
tf.stack(question_difficulties, axis=1),
[self.args.batch_size, self.args.seq_len])
logger.debug("Shape of pred_z_values: {}".format(self.pred_z_values))
logger.debug("Shape of student_abilities: {}".format(
self.student_abilities))
logger.debug("Shape of question_difficulties: {}".format(
self.question_difficulties))
def _create_loss(self):
logger.info("Initializing Loss Function")
# convert into 1D
label_1d = tf.reshape(self.label, [-1])
pred_z_values_1d = tf.reshape(self.pred_z_values, [-1])
student_abilities_1d = tf.reshape(self.student_abilities, [-1])
question_difficulties_1d = tf.reshape(self.question_difficulties, [-1])
# find the label index that is not masking
index = tf.where(
tf.not_equal(label_1d, tf.constant(-1., dtype=tf.float32)))
# masking
filtered_label = tf.gather(label_1d, index)
filtered_z_values = tf.gather(pred_z_values_1d, index)
filtered_student_abilities = tf.gather(student_abilities_1d, index)
filtered_question_difficulties = tf.gather(question_difficulties_1d,
index)
logger.debug("Shape of filtered_label: {}".format(filtered_label))
logger.debug(
"Shape of filtered_z_values: {}".format(filtered_z_values))
logger.debug("Shape of filtered_student_abilities: {}".format(
filtered_student_abilities))
logger.debug("Shape of filtered_question_difficulties: {}".format(
filtered_question_difficulties))
if self.args.use_ogive_model:
# make prediction using normal ogive model
dist = tfd.Normal(loc=0.0, scale=1.0)
self.pred = dist.cdf(pred_z_values_1d)
filtered_pred = dist.cdf(filtered_z_values)
else:
self.pred = tf.math.sigmoid(pred_z_values_1d)
filtered_pred = tf.math.sigmoid(filtered_z_values)
# convert the prediction probability to logit, i.e., log(p/(1-p))
epsilon = 1e-6
clipped_filtered_pred = tf.clip_by_value(filtered_pred, epsilon,
1. - epsilon)
filtered_logits = tf.log(clipped_filtered_pred /
(1 - clipped_filtered_pred))
# cross entropy loss
cross_entropy = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(logits=filtered_logits,
labels=filtered_label))
self.loss = cross_entropy
def _create_optimizer(self):
with tf.variable_scope('Optimizer'):
self.optimizer = tf.train.AdamOptimizer(
learning_rate=self.args.learning_rate)
gvs = self.optimizer.compute_gradients(self.loss)
clipped_gvs = [(tf.clip_by_norm(grad,
self.args.max_grad_norm), var)
for grad, var in gvs]
self.train_op = self.optimizer.apply_gradients(clipped_gvs)
def _add_summary(self):
tf.summary.scalar('Loss', self.loss)
self.tensorboard_writer = tf.summary.FileWriter(
logdir=self.args.tensorboard_dir, graph=self.sess.graph)
model_vars = tf.trainable_variables()
total_size = 0
total_bytes = 0
model_msg = ""
for var in model_vars:
# if var.num_elements() is None or [] assume size 0.
var_size = var.get_shape().num_elements() or 0
var_bytes = var_size * var.dtype.size
total_size += var_size
total_bytes += var_bytes
model_msg += ' '.join([
var.name,
tensor_description(var),
'[%d, bytes: %d]' % (var_size, var_bytes)
])
model_msg += '\n'
model_msg += 'Total size of variables: %d \n' % total_size
model_msg += 'Total bytes of variables: %d \n' % total_bytes
logger.info(model_msg)
def sym_gen(self):
### TODO input variable 'q_data'
q_data = mx.sym.Variable('q_data', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### TODO input variable 'qa_data'
qa_data = mx.sym.Variable('qa_data', shape=(self.seqlen, self.batch_size)) # (seqlen, batch_size)
### TODO input variable 'target'
target = mx.sym.Variable('target', shape=(self.seqlen, self.batch_size)) #(seqlen, batch_size)
### Initialize Memory
init_memory_key = mx.sym.Variable('init_memory_key_weight')
init_memory_value = mx.sym.Variable('init_memory_value',
shape=(self.memory_size, self.memory_value_state_dim),
init=mx.init.Normal(0.1)) # (self.memory_size, self.memory_value_state_dim)
init_memory_value = mx.sym.broadcast_to(mx.sym.expand_dims(init_memory_value, axis=0),
shape=(self.batch_size, self.memory_size, self.memory_value_state_dim))
mem = DKVMN(memory_size=self.memory_size,
memory_key_state_dim=self.memory_key_state_dim,
memory_value_state_dim=self.memory_value_state_dim,
init_memory_key=init_memory_key,
init_memory_value=init_memory_value,
name="DKVMN")
### embedding
q_data = mx.sym.BlockGrad(q_data)
q_embed_data = mx.sym.Embedding(data=q_data, input_dim=self.n_question+1,
output_dim=self.q_embed_dim, name='q_embed')
slice_q_embed_data = mx.sym.SliceChannel(q_embed_data, num_outputs=self.seqlen, axis=0, squeeze_axis=True)
qa_data = mx.sym.BlockGrad(qa_data)
qa_embed_data = mx.sym.Embedding(data=qa_data, input_dim=self.n_question*2+1,
output_dim=self.qa_embed_dim, name='qa_embed')
slice_qa_embed_data = mx.sym.SliceChannel(qa_embed_data, num_outputs=self.seqlen, axis=0, squeeze_axis=True)
value_read_content_l = []
input_embed_l = []
for i in range(self.seqlen):
## Attention
q = slice_q_embed_data[i]
correlation_weight = mem.attention(q)
## Read Process
read_content = mem.read(correlation_weight) #Shape (batch_size, memory_state_dim)
### save intermedium data
value_read_content_l.append(read_content)
input_embed_l.append(q)
## Write Process
qa = slice_qa_embed_data[i]
new_memory_value = mem.write(correlation_weight, qa)
all_read_value_content = mx.sym.Concat(*value_read_content_l, num_args=self.seqlen, dim=0)
input_embed_content = mx.sym.Concat(*input_embed_l, num_args=self.seqlen, dim=0)
input_embed_content = mx.sym.FullyConnected(data=input_embed_content, num_hidden=50, name="input_embed_content")
input_embed_content = mx.sym.Activation(data=input_embed_content, act_type='tanh', name="input_embed_content_tanh")
read_content_embed = mx.sym.FullyConnected(data=mx.sym.Concat(all_read_value_content, input_embed_content, num_args=2, dim=1),
num_hidden=self.final_fc_dim, name="read_content_embed")
read_content_embed = mx.sym.Activation(data=read_content_embed, act_type='tanh', name="read_content_embed_tanh")
pred = mx.sym.FullyConnected(data=read_content_embed, num_hidden=1, name="final_fc")
pred_prob = logistic_regression_mask_output(data=mx.sym.Reshape(pred, shape=(-1, )),
label=mx.sym.Reshape(data=target, shape=(-1,)),
ignore_label=-1., name='final_pred')
return mx.sym.Group([pred_prob])
class MODEL(nn.Module):
def __init__(self,
n_question,
batch_size,
q_embed_dim,
qa_embed_dim,
memory_size,
memory_key_state_dim,
memory_value_state_dim,
final_fc_dim,
first_k,
gpu,
student_num=None):
super(MODEL, self).__init__()
self.n_question = n_question
self.batch_size = batch_size
self.q_embed_dim = q_embed_dim
self.qa_embed_dim = qa_embed_dim
self.memory_size = memory_size
self.memory_key_state_dim = memory_key_state_dim
self.memory_value_state_dim = memory_value_state_dim
self.final_fc_dim = final_fc_dim
self.student_num = student_num
self.first_k = first_k
self.read_embed_linear = nn.Linear(self.memory_value_state_dim +
self.q_embed_dim,
self.final_fc_dim,
bias=True)
# self.predict_linear = nn.Linear(self.memory_value_state_dim + self.q_embed_dim, 1, bias=True)
self.init_memory_key = nn.Parameter(
torch.randn(self.memory_size, self.memory_key_state_dim))
nn.init.kaiming_normal_(self.init_memory_key)
self.init_memory_value = nn.Parameter(
torch.randn(self.memory_size, self.memory_value_state_dim))
nn.init.kaiming_normal_(self.init_memory_value)
# modify hop_lstm
self.hop_lstm = nn.LSTM(input_size=self.memory_value_state_dim +
self.q_embed_dim,
hidden_size=64,
num_layers=1,
batch_first=True)
# hidden_size = 64
self.predict_linear = nn.Linear(64, 1, bias=True)
self.mem = DKVMN(memory_size=self.memory_size,
memory_key_state_dim=self.memory_key_state_dim,
memory_value_state_dim=self.memory_value_state_dim,
init_memory_key=self.init_memory_key)
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data)
self.mem.init_value_memory(memory_value)
# 题目序号从1开始
# nn.embedding输入是一个下标的列标，输出是对应的嵌入
self.q_embed = nn.Embedding(self.n_question + 1,
self.q_embed_dim,
padding_idx=0)
self.a_embed = nn.Linear(2 * self.n_question + 1,
self.qa_embed_dim,
bias=True)
# self.a_embed = nn.Linear(self.final_fc_dim + 1, self.qa_embed_dim, bias=True)
# self.correlation_weight_list = []
if gpu >= 0:
self.device = torch.device('cuda', gpu)
else:
self.device = torch.device('cpu')
print(
"num_layers=1, hidden_size=64, a=0.075, b=0.088, c=1.00, triangular, onehot"
)
def init_params(self):
nn.init.kaiming_normal_(self.predict_linear.weight)
nn.init.kaiming_normal_(self.read_embed_linear.weight)
nn.init.constant_(self.read_embed_linear.bias, 0)
nn.init.constant_(self.predict_linear.bias, 0)
def init_embeddings(self):
nn.init.kaiming_normal_(self.q_embed.weight)
# 方法2：权重向量的topk置1
def identity_layer(self, correlation_weight, seqlen, k=1):
batch_identity_indices = []
correlation_weight = correlation_weight.view(self.batch_size * seqlen,
-1)
# 把batch中每一格sequence中topk置1，其余置0
_, indices = correlation_weight.topk(k, dim=1, largest=True)
identity_matrix = torch.zeros(
[self.batch_size * seqlen, self.memory_size])
for i, m in enumerate(indices):
identity_matrix[i, m] = 1
identity_vector_batch = identity_matrix.view(self.batch_size * seqlen,
-1)
unique_iv = torch.unique(identity_vector_batch, sorted=False, dim=0)
self.unique_len = unique_iv.shape[0]
# A^2
iv_square_norm = torch.sum(torch.pow(identity_vector_batch, 2),
dim=1,
keepdim=True)
iv_square_norm = iv_square_norm.repeat((1, self.unique_len))
# B^2.T
unique_iv_square_norm = torch.sum(torch.pow(unique_iv, 2),
dim=1,
keepdim=True)
unique_iv_square_norm = unique_iv_square_norm.repeat(
(1, self.batch_size * seqlen)).transpose(1, 0)
# A * B.T
iv_matrix_product = identity_vector_batch.mm(unique_iv.transpose(1, 0))
# A^2 + B^2 - 2A*B.T
iv_distances = iv_square_norm + unique_iv_square_norm - 2 * iv_matrix_product
indices = (iv_distances == 0).nonzero()
batch_identity_indices = indices[:, -1]
return batch_identity_indices
# 方法1：用三角隶属函数计算identity向量
def triangular_layer(self,
correlation_weight,
seqlen,
a=0.075,
b=0.088,
c=1.00):
batch_identity_indices = []
# w'= max((w-a)/(b-a), (c-w)/(c-b))
# min(w', 0)
correlation_weight = correlation_weight.view(self.batch_size * seqlen,
-1)
correlation_weight = torch.cat([
correlation_weight[i] for i in range(correlation_weight.shape[0])
], 0).unsqueeze(0)
correlation_weight = torch.cat([(correlation_weight - a) / (b - a),
(c - correlation_weight) / (c - b)], 0)
correlation_weight, _ = torch.min(correlation_weight, 0)
w0 = torch.zeros(correlation_weight.shape[0]).to(self.device)
correlation_weight = torch.cat(
[correlation_weight.unsqueeze(0),
w0.unsqueeze(0)], 0)
correlation_weight, _ = torch.max(correlation_weight, 0)
identity_vector_batch = torch.zeros(correlation_weight.shape[0]).to(
self.device)
# >=0.6的值置2，0.1-0.6的值置1，0.1以下的值置0
# mask = correlation_weight.lt(0.1)
identity_vector_batch = identity_vector_batch.masked_fill(
correlation_weight.lt(0.1), 0)
# mask = correlation_weight.ge(0.1)
identity_vector_batch = identity_vector_batch.masked_fill(
correlation_weight.ge(0.1), 1)
# mask = correlation_weight.ge(0.6)
_identity_vector_batch = identity_vector_batch.masked_fill(
correlation_weight.ge(0.6), 2)
# identity_vector_batch = torch.chunk(identity_vector_batch.view(self.batch_size, -1), self.batch_size, 0)
# 输入：_identity_vector_batch
# 输出：indices
identity_vector_batch = _identity_vector_batch.view(
self.batch_size * seqlen, -1)
unique_iv = torch.unique(identity_vector_batch, sorted=False, dim=0)
self.unique_len = unique_iv.shape[0]
# A^2
iv_square_norm = torch.sum(torch.pow(identity_vector_batch, 2),
dim=1,
keepdim=True)
iv_square_norm = iv_square_norm.repeat((1, self.unique_len))
# B^2.T
unique_iv_square_norm = torch.sum(torch.pow(unique_iv, 2),
dim=1,
keepdim=True)
unique_iv_square_norm = unique_iv_square_norm.repeat(
(1, self.batch_size * seqlen)).transpose(1, 0)
# A * B.T
iv_matrix_product = identity_vector_batch.mm(unique_iv.transpose(1, 0))
# A^2 + B^2 - 2A*B.T
iv_distances = iv_square_norm + unique_iv_square_norm - 2 * iv_matrix_product
indices = (iv_distances == 0).nonzero()
batch_identity_indices = indices[:, -1]
return batch_identity_indices
def forward(self, q_data, qa_data, a_data, target, student_id=None):
batch_size = q_data.shape[0] #32
seqlen = q_data.shape[1] #200
## qt && (q,a) embedding
q_embed_data = self.q_embed(q_data)
# modify 生成每道题对应的yt onehot向量
a_onehot_array = []
for i in range(a_data.shape[0]):
for j in range(a_data.shape[1]):
a_onehot = np.zeros(self.n_question + 1)
index = a_data[i][j]
if index > 0:
a_onehot[index] = 1
a_onehot_array.append(a_onehot)
a_onehot_content = torch.cat([
torch.Tensor(a_onehot_array[i]).unsqueeze(0)
for i in range(len(a_onehot_array))
], 0)
a_onehot_content = a_onehot_content.view(batch_size, seqlen,
-1).to(self.device)
## copy mk batch times for dkvmn
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data)
self.mem.init_value_memory(memory_value)
## slice data for seqlen times by axis 1
slice_q_data = torch.chunk(q_data, seqlen, 1)
slice_q_embed_data = torch.chunk(q_embed_data, seqlen, 1)
# modify
slice_a_onehot_content = torch.chunk(a_onehot_content, seqlen, 1)
# slice_a = torch.chunk(a_data, seqlen, 1)
value_read_content_l = []
input_embed_l = []
correlation_weight_list = []
# modify
f_t = []
# (n_layers，batch_size，hidden_dim)
init_h = torch.randn(1, self.batch_size, 64).to(self.device)
init_c = torch.randn(1, self.batch_size, 64).to(self.device)
for i in range(seqlen):
## Attention
q = slice_q_embed_data[i].squeeze(1)
correlation_weight = self.mem.attention(q)
## Read Process
read_content = self.mem.read(correlation_weight)
# modify
correlation_weight_list.append(correlation_weight)
## save intermedium data
value_read_content_l.append(read_content)
input_embed_l.append(q)
# modify
batch_predict_input = torch.cat([read_content, q], 1)
f = self.read_embed_linear(batch_predict_input)
f_t.append(batch_predict_input)
# 写入value矩阵的输入为[yt, ft]，onehot向量和ft向量拼接
onehot = slice_a_onehot_content[i].squeeze(1)
write_embed = torch.cat([onehot, f], 1)
# 写入value矩阵的输入为[ft, yt]，ft直接和题目对错（0或1）拼接
# write_embed = torch.cat([f, slice_a[i].float()], 1)
write_embed = self.a_embed(write_embed)
new_memory_value = self.mem.write(correlation_weight, write_embed)
# modify
correlation_weight_matrix = torch.cat(
[correlation_weight_list[i].unsqueeze(1) for i in range(seqlen)],
1)
identity_index_list = self.triangular_layer(correlation_weight_matrix,
seqlen)
# identity_index_list = self.identity_layer(correlation_weight_matrix, seqlen)
identity_index_list = identity_index_list.view(self.batch_size, seqlen)
# identity_index_list = identity_index_list[:, self.first_k:] # 前k个不进行预测
# identity_index_list = torch.cat([identity_index_list[i].unsqueeze(1) for i in range(seqlen)], 1)
f_t = torch.cat([f_t[i].unsqueeze(1) for i in range(seqlen)], 1)
# f_t = f_t[:, self.first_k:] # 前k个不进行预测
target_seqlayer = target.view(batch_size, seqlen, -1)
# target_seqlayer = target_seqlayer[:, self.first_k:] # 前k个不进行预测
target_sequence = []
pred_sequence = []
for idx in range(self.unique_len):
# start = time.time()
hop_lstm_input = []
hop_lstm_target = []
max_seq = 1
zero_count = 0
for i in range(self.batch_size):
# 获取每个sequence中和当前要进行预测的identity向量对应的题目在矩阵中的index
index = list((identity_index_list[i, :] == idx).nonzero())
max_seq = max(max_seq, len(index))
if len(index) == 0:
hop_lstm_input.append(
torch.zeros([
1, self.memory_value_state_dim + self.q_embed_dim
]))
hop_lstm_target.append(torch.full([1, 1], -1))
zero_count += 1
continue
else:
index = torch.LongTensor(index).to(self.device)
hop_lstm_target_slice = torch.index_select(
target_seqlayer[i, :, :], 0, index)
hop_lstm_input_slice = torch.index_select(
f_t[i, :, :], 0, index)
hop_lstm_input.append(hop_lstm_input_slice)
hop_lstm_target.append(hop_lstm_target_slice)
if zero_count == 32:
continue
# 给输入矩阵和target矩阵做padding
for i in range(self.batch_size):
x = torch.zeros(
[max_seq, self.memory_value_state_dim + self.q_embed_dim])
x[:len(hop_lstm_input[i]), :] = hop_lstm_input[i]
hop_lstm_input[i] = x
y = torch.full([max_seq, 1], -1)
y[:len(hop_lstm_target[i]), :] = hop_lstm_target[i]
hop_lstm_target[i] = y
# hop lstm进行预测
hop_lstm_input = torch.cat([
hop_lstm_input[i].unsqueeze(0) for i in range(self.batch_size)
], 0).to(self.device)
hop_lstm_target = torch.cat([
hop_lstm_target[i].unsqueeze(0) for i in range(self.batch_size)
], 0)
hop_lstm_output, _ = self.hop_lstm(hop_lstm_input,
(init_h, init_c))
pred = self.predict_linear(hop_lstm_output)
pred = pred.view(self.batch_size * max_seq, -1)
hop_lstm_target = hop_lstm_target.view(self.batch_size * max_seq,
-1).to(self.device)
mask = hop_lstm_target.ge(0)
hop_lstm_target = torch.masked_select(hop_lstm_target, mask)
pred = torch.sigmoid(torch.masked_select(pred, mask))
target_sequence.append(hop_lstm_target)
pred_sequence.append(pred)
# 在训练阶段对每个identity向量对应的lstm分别进行反向传播
if self.training is True:
subsequence_loss = torch.nn.functional.binary_cross_entropy_with_logits(
pred, hop_lstm_target)
subsequence_loss.backward(retain_graph=True)
# 计算一个batch全部题目的loss
target_sequence = torch.cat(
[target_sequence[i] for i in range(len(target_sequence))], 0)
pred_sequence = torch.cat(
[pred_sequence[i] for i in range(len(pred_sequence))], 0)
loss = torch.nn.functional.binary_cross_entropy_with_logits(
pred_sequence, target_sequence)
return loss, pred_sequence, target_sequence
def __init__(self,
n_question,
batch_size,
q_embed_dim,
qa_embed_dim,
memory_size,
memory_key_state_dim,
memory_value_state_dim,
final_fc_dim,
first_k,
gpu,
student_num=None):
super(MODEL, self).__init__()
self.n_question = n_question
self.batch_size = batch_size
self.q_embed_dim = q_embed_dim
self.qa_embed_dim = qa_embed_dim
self.memory_size = memory_size
self.memory_key_state_dim = memory_key_state_dim
self.memory_value_state_dim = memory_value_state_dim
self.final_fc_dim = final_fc_dim
self.student_num = student_num
self.first_k = first_k
self.read_embed_linear = nn.Linear(self.memory_value_state_dim +
self.q_embed_dim,
self.final_fc_dim,
bias=True)
# self.predict_linear = nn.Linear(self.memory_value_state_dim + self.q_embed_dim, 1, bias=True)
self.init_memory_key = nn.Parameter(
torch.randn(self.memory_size, self.memory_key_state_dim))
nn.init.kaiming_normal_(self.init_memory_key)
self.init_memory_value = nn.Parameter(
torch.randn(self.memory_size, self.memory_value_state_dim))
nn.init.kaiming_normal_(self.init_memory_value)
# modify hop_lstm
self.hop_lstm = nn.LSTM(input_size=self.memory_value_state_dim +
self.q_embed_dim,
hidden_size=64,
num_layers=1,
batch_first=True)
# hidden_size = 64
self.predict_linear = nn.Linear(64, 1, bias=True)
self.mem = DKVMN(memory_size=self.memory_size,
memory_key_state_dim=self.memory_key_state_dim,
memory_value_state_dim=self.memory_value_state_dim,
init_memory_key=self.init_memory_key)
memory_value = nn.Parameter(
torch.cat([
self.init_memory_value.unsqueeze(0) for _ in range(batch_size)
], 0).data)
self.mem.init_value_memory(memory_value)
# 题目序号从1开始
# nn.embedding输入是一个下标的列标，输出是对应的嵌入
self.q_embed = nn.Embedding(self.n_question + 1,
self.q_embed_dim,
padding_idx=0)
self.a_embed = nn.Linear(2 * self.n_question + 1,
self.qa_embed_dim,
bias=True)
# self.a_embed = nn.Linear(self.final_fc_dim + 1, self.qa_embed_dim, bias=True)
# self.correlation_weight_list = []
if gpu >= 0:
self.device = torch.device('cuda', gpu)
else:
self.device = torch.device('cpu')
print(
"num_layers=1, hidden_size=64, a=0.075, b=0.088, c=1.00, triangular, onehot"
)
class Model():
def __init__(self, args, sess, name='KT'):
self.args = args
self.name = name
self.sess = sess
# Initialize Memory
with tf.variable_scope('Memory'):
init_memory_key = tf.get_variable('key', [self.args.memory_size, self.args.memory_key_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_memory_value = tf.get_variable('value', [self.args.memory_size,self.args.memory_value_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Broadcast memory value tensor to match [batch size, memory size, memory state dim]
# First expand dim at axis 0 so that makes 'batch size' axis and tile it along 'batch size' axis
# tf.tile(inputs, multiples) : multiples length must be thes saame as the number of dimensions in input
# tf.stack takes a list and convert each element to a tensor
init_memory_value = tf.tile(tf.expand_dims(init_memory_value, 0), tf.stack([self.args.batch_size, 1, 1]))
print(init_memory_value.get_shape())
self.memory = DKVMN(self.args.memory_size, self.args.memory_key_state_dim, \
self.args.memory_value_state_dim, init_memory_key=init_memory_key, init_memory_value=init_memory_value, name='DKVMN')
# Embedding to [batch size, seq_len, memory_state_dim(d_k or d_v)]
with tf.variable_scope('Embedding'):
# A
self.q_embed_mtx = tf.get_variable('q_embed', [self.args.n_questions+1, self.args.memory_key_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
# B
self.qa_embed_mtx = tf.get_variable('qa_embed', [2*self.args.n_questions+1, self.args.memory_value_state_dim], initializer=tf.truncated_normal_initializer(stddev=0.1))
self.prediction = self.build_network(reuse_flag=False)
self.build_optimizer()
#self.create_model()
def build_network(self, reuse_flag):
print('Building network')
self.q_data = tf.placeholder(tf.int32, [self.args.batch_size], name='q_data')
self.qa_data = tf.placeholder(tf.int32, [self.args.batch_size], name='qa_data')
self.target = tf.placeholder(tf.float32, [self.args.batch_size], name='target')
# Embedding to [batch size, seq_len, memory key state dim]
q_embed_data = tf.nn.embedding_lookup(self.q_embed_mtx, self.q_data)
# List of [batch size, 1, memory key state dim] with 'seq_len' elements
#print('Q_embedding shape : %s' % q_embed_data.get_shape())
#slice_q_embed_data = tf.split(q_embed_data, self.args.seq_len, 1)
#print(len(slice_q_embed_data), type(slice_q_embed_data), slice_q_embed_data[0].get_shape())
# Embedding to [batch size, seq_len, memory value state dim]
qa_embed_data = tf.nn.embedding_lookup(self.qa_embed_mtx, self.qa_data)
#print('QA_embedding shape: %s' % qa_embed_data.get_shape())
# List of [batch size, 1, memory value state dim] with 'seq_len' elements
#slice_qa_embed_data = tf.split(qa_embed_data, self.args.seq_len, 1)
#prediction = list()
#reuse_flag = False
# k_t : [batch size, memory key state dim]
#q = tf.squeeze(slice_q_embed_data[i], 1)
# Attention, [batch size, memory size]
self.correlation_weight = self.memory.attention(q_embed_data)
# Read process, [batch size, memory value state dim]
self.read_content = self.memory.read(self.correlation_weight)
# Write process, [batch size, memory size, memory value state dim]
# qa : [batch size, memory value state dim]
#qa = tf.squeeze(slice_qa_embed_data[i], 1)
# Only last time step value is necessary
self.new_memory_value = self.memory.write(self.correlation_weight, qa_embed_data, reuse=reuse_flag)
mastery_level_prior_difficulty = tf.concat([self.read_content, q_embed_data], 1)
# f_t
summary_vector = tf.tanh(operations.linear(mastery_level_prior_difficulty, self.args.final_fc_dim, name='Summary_Vector', reuse=reuse_flag))
# p_t
pred_logits = operations.linear(summary_vector, 1, name='Prediction', reuse=reuse_flag)
return pred_logits
def build_optimizer(self):
print('Building optimizer')
# 'seq_len' means question sequences
self.q_data_seq = tf.placeholder(tf.int32, [self.args.batch_size, self.args.seq_len], name='q_data_seq')
self.qa_data_seq = tf.placeholder(tf.int32, [self.args.batch_size, self.args.seq_len], name='qa_data_seq')
self.target_seq = tf.placeholder(tf.float32, [self.args.batch_size, self.args.seq_len], name='target_seq')
# Embedding to [batch size, seq_len, memory key state dim]
#q_embed_data = tf.nn.embedding_lookup(q_embed_mtx, self.q_data_seq)
# List of [batch size, 1, memory key state dim] with 'seq_len' elements
#print('Q_embedding shape : %s' % q_embed_data.get_shape())
slice_q_data = tf.split(self.q_data_seq, self.args.seq_len, 1)
#print(len(slice_q_embed_data), type(slice_q_embed_data), slice_q_embed_data[0].get_shape())
# Embedding to [batch size, seq_len, memory value state dim]
#qa_embed_data = tf.nn.embedding_lookup(qa_embed_mtx, self.qa_data_seq)
#print('QA_embedding shape: %s' % qa_embed_data.get_shape())
# List of [batch size, 1, memory value state dim] with 'seq_len' elements
slice_qa_data = tf.split(self.qa_data_seq, self.args.seq_len, 1)
prediction = list()
reuse_flag = False
# Logics
for i in range(self.args.seq_len):
# To reuse linear vectors
q = tf.squeeze(slice_q_data[i], 1)
# Attention, [batch size, memory size]
qa = tf.squeeze(slice_qa_data[i], 1)
# Only last time step value is necessary
pred_logits =
prediction.append(pred_logits)
# 'prediction' : seq_len length list of [batch size ,1], make it [batch size, seq_len] tensor
# tf.stack convert to [batch size, seq_len, 1]
self.pred_logits = tf.reshape(tf.stack(prediction, axis=1), [self.args.batch_size, self.args.seq_len])
# Define loss : standard cross entropy loss, need to ignore '-1' label example
# Make target/label 1-d array
target_1d = tf.reshape(self.target_seq, [-1])
pred_logits_1d = tf.reshape(self.pred_logits, [-1])
index = tf.where(tf.not_equal(target_1d, tf.constant(-1., dtype=tf.float32)))
# tf.gather(params, indices) : Gather slices from params according to indices
filtered_target = tf.gather(target_1d, index)
filtered_logits = tf.gather(pred_logits_1d, index)
self.loss = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(logits=filtered_logits, labels=filtered_target))
self.pred = tf.sigmoid(self.pred_logits)
# Optimizer : SGD + MOMENTUM with learning rate decay
self.global_step = tf.Variable(0, trainable=False)
self.lr = tf.placeholder(tf.float32, [], name='learning_rate')
# self.lr_decay = tf.train.exponential_decay(self.args.initial_lr, global_step=global_step, decay_steps=10000, decay_rate=0.667, staircase=True)
# self.learning_rate = tf.maximum(lr, self.args.lr_lowerbound)
optimizer = tf.train.MomentumOptimizer(self.lr, self.args.momentum)
grads, vrbs = zip(*optimizer.compute_gradients(self.loss))
grad, _ = tf.clip_by_global_norm(grads, self.args.maxgradnorm)
self.train_op = optimizer.apply_gradients(zip(grad, vrbs), global_step=self.global_step)
# grad_clip = [(tf.clip_by_value(grad, -self.args.maxgradnorm, self.args.maxgradnorm), var) for grad, var in grads]
self.tr_vrbs = tf.trainable_variables()
for i in self.tr_vrbs:
print(i.name)
self.saver = tf.train.Saver()
def create_model(self):
# 'seq_len' means question sequences
self.q_data_seq = tf.placeholder(tf.int32, [self.args.batch_size, self.args.seq_len], name='q_data_seq')
self.qa_data_seq = tf.placeholder(tf.int32, [self.args.batch_size, self.args.seq_len], name='qa_data')
self.target_seq = tf.placeholder(tf.float32, [self.args.batch_size, self.args.seq_len], name='target')
'''
# Initialize Memory
with tf.variable_scope('Memory'):
init_memory_key = tf.get_variable('key', [self.args.memory_size, self.args.memory_key_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
init_memory_value = tf.get_variable('value', [self.args.memory_size,self.args.memory_value_state_dim], \
initializer=tf.truncated_normal_initializer(stddev=0.1))
# Broadcast memory value tensor to match [batch size, memory size, memory state dim]
# First expand dim at axis 0 so that makes 'batch size' axis and tile it along 'batch size' axis
# tf.tile(inputs, multiples) : multiples length must be thes saame as the number of dimensions in input
# tf.stack takes a list and convert each element to a tensor
init_memory_value = tf.tile(tf.expand_dims(init_memory_value, 0), tf.stack([self.args.batch_size, 1, 1]))
print(init_memory_value.get_shape())
self.memory = DKVMN(self.args.memory_size, self.args.memory_key_state_dim, \
self.args.memory_value_state_dim, init_memory_key=init_memory_key, init_memory_value=init_memory_value, name='DKVMN')
# Embedding to [batch size, seq_len, memory_state_dim(d_k or d_v)]
with tf.variable_scope('Embedding'):
# A
q_embed_mtx = tf.get_variable('q_embed', [self.args.n_questions+1, self.args.memory_key_state_dim],\
initializer=tf.truncated_normal_initializer(stddev=0.1))
# B
qa_embed_mtx = tf.get_variable('qa_embed', [2*self.args.n_questions+1, self.args.memory_value_state_dim], initializer=tf.truncated_normal_initializer(stddev=0.1))
'''
# Embedding to [batch size, seq_len, memory key state dim]
q_embed_data = tf.nn.embedding_lookup(self.q_embed_mtx, self.q_data_seq)
# List of [batch size, 1, memory key state dim] with 'seq_len' elements
#print('Q_embedding shape : %s' % q_embed_data.get_shape())
slice_q_embed_data = tf.split(q_embed_data, self.args.seq_len, 1)
#print(len(slice_q_embed_data), type(slice_q_embed_data), slice_q_embed_data[0].get_shape())
# Embedding to [batch size, seq_len, memory value state dim]
qa_embed_data = tf.nn.embedding_lookup(self.qa_embed_mtx, self.qa_data_seq)
#print('QA_embedding shape: %s' % qa_embed_data.get_shape())
# List of [batch size, 1, memory value state dim] with 'seq_len' elements
slice_qa_embed_data = tf.split(qa_embed_data, self.args.seq_len, 1)
prediction = list()
reuse_flag = False
# Logics
for i in range(self.args.seq_len):
# To reuse linear vectors
if i != 0:
reuse_flag = True
# k_t : [batch size, memory key state dim]
q = tf.squeeze(slice_q_embed_data[i], 1)
# Attention, [batch size, memory size]
self.correlation_weight = self.memory.attention(q)
# Read process, [batch size, memory value state dim]
self.read_content = self.memory.read(self.correlation_weight)
# Write process, [batch size, memory size, memory value state dim]
# qa : [batch size, memory value state dim]
qa = tf.squeeze(slice_qa_embed_data[i], 1)
# Only last time step value is necessary
self.new_memory_value = self.memory.write(self.correlation_weight, qa, reuse=reuse_flag)
mastery_level_prior_difficulty = tf.concat([self.read_content, q], 1)
# f_t
summary_vector = tf.tanh(operations.linear(mastery_level_prior_difficulty, self.args.final_fc_dim, name='Summary_Vector', reuse=reuse_flag))
# p_t
pred_logits = operations.linear(summary_vector, 1, name='Prediction', reuse=reuse_flag)
prediction.append(pred_logits)
# 'prediction' : seq_len length list of [batch size ,1], make it [batch size, seq_len] tensor
# tf.stack convert to [batch size, seq_len, 1]
self.pred_logits = tf.reshape(tf.stack(prediction, axis=1), [self.args.batch_size, self.args.seq_len])
# Define loss : standard cross entropy loss, need to ignore '-1' label example
# Make target/label 1-d array
target_1d = tf.reshape(self.target_seq, [-1])
pred_logits_1d = tf.reshape(self.pred_logits, [-1])
index = tf.where(tf.not_equal(target_1d, tf.constant(-1., dtype=tf.float32)))
# tf.gather(params, indices) : Gather slices from params according to indices
filtered_target = tf.gather(target_1d, index)
filtered_logits = tf.gather(pred_logits_1d, index)
self.loss = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(logits=filtered_logits, labels=filtered_target))
self.pred = tf.sigmoid(self.pred_logits)
# Optimizer : SGD + MOMENTUM with learning rate decay
self.global_step = tf.Variable(0, trainable=False)
self.lr = tf.placeholder(tf.float32, [], name='learning_rate')
# self.lr_decay = tf.train.exponential_decay(self.args.initial_lr, global_step=global_step, decay_steps=10000, decay_rate=0.667, staircase=True)
# self.learning_rate = tf.maximum(lr, self.args.lr_lowerbound)
optimizer = tf.train.MomentumOptimizer(self.lr, self.args.momentum)
grads, vrbs = zip(*optimizer.compute_gradients(self.loss))
grad, _ = tf.clip_by_global_norm(grads, self.args.maxgradnorm)
self.train_op = optimizer.apply_gradients(zip(grad, vrbs), global_step=self.global_step)
# grad_clip = [(tf.clip_by_value(grad, -self.args.maxgradnorm, self.args.maxgradnorm), var) for grad, var in grads]
self.tr_vrbs = tf.trainable_variables()
for i in self.tr_vrbs:
print(i.name)
self.saver = tf.train.Saver()
def train(self, train_q_data, train_qa_data, valid_q_data, valid_qa_data):
# q_data, qa_data : [samples, seq_len]
shuffle_index = np.random.permutation(train_q_data.shape[0])
q_data_shuffled = train_q_data[shuffle_index]
qa_data_shuffled = train_qa_data[shuffle_index]
training_step = train_q_data.shape[0] // self.args.batch_size
self.sess.run(tf.global_variables_initializer())
if self.args.show:
from utils import ProgressBar
bar = ProgressBar(label, max=training_step)
self.train_count = 0
if self.args.init_from:
if self.load():
print('Checkpoint_loaded')
else:
print('No checkpoint')
else:
if os.path.exists(os.path.join(self.args.checkpoint_dir, self.model_dir)):
try:
shutil.rmtree(os.path.join(self.args.checkpoint_dir, self.model_dir))
shutil.rmtree(os.path.join(self.args.log_dir, self.model_dir+'.csv'))
except(FileNotFoundError, IOError) as e:
print('[Delete Error] %s - %s' % (e.filename, e.strerror))
best_valid_auc = 0
# Training
for epoch in range(0, self.args.num_epochs):
if self.args.show:
bar.next()
pred_list = list()
target_list = list()
epoch_loss = 0
learning_rate = tf.train.exponential_decay(self.args.initial_lr, global_step=self.global_step, decay_steps=self.args.anneal_interval*training_step, decay_rate=0.667, staircase=True)
#print('Epoch %d starts with learning rate : %3.5f' % (epoch+1, self.sess.run(learning_rate)))
for steps in range(training_step):
# [batch size, seq_len]
q_batch_seq = q_data_shuffled[steps*self.args.batch_size:(steps+1)*self.args.batch_size, :]
qa_batch_seq = qa_data_shuffled[steps*self.args.batch_size:(steps+1)*self.args.batch_size, :]
# qa : exercise index + answer(0 or 1)*exercies_number
# right : 1, wrong : 0, padding : -1
target = qa_batch_seq[:,:]
# Make integer type to calculate target
target = target.astype(np.int)
target_batch = (target - 1) // self.args.n_questions
target_batch = target_batch.astype(np.float)
feed_dict = {self.q_data_seq:q_batch_seq, self.qa_data_seq:qa_batch_seq, self.target_seq:target_batch, self.lr:self.args.initial_lr}
#self.lr:self.sess.run(learning_rate)
loss_, pred_, _, = self.sess.run([self.loss, self.pred, self.train_op], feed_dict=feed_dict)
# Get right answer index
# Make [batch size * seq_len, 1]
right_target = np.asarray(target_batch).reshape(-1,1)
right_pred = np.asarray(pred_).reshape(-1,1)
# np.flatnonzero returns indices which is nonzero, convert it list
right_index = np.flatnonzero(right_target != -1.).tolist()
# Number of 'training_step' elements list with [batch size * seq_len, ]
pred_list.append(right_pred[right_index])
target_list.append(right_target[right_index])
epoch_loss += loss_
#print('Epoch %d/%d, steps %d/%d, loss : %3.5f' % (epoch+1, self.args.num_epochs, steps+1, training_step, loss_))
if self.args.show:
bar.finish()
all_pred = np.concatenate(pred_list, axis=0)
all_target = np.concatenate(target_list, axis=0)
# Compute metrics
self.auc = metrics.roc_auc_score(all_target, all_pred)
# Extract elements with boolean index
# Make '1' for elements higher than 0.5
# Make '0' for elements lower than 0.5
all_pred[all_pred > 0.5] = 1
all_pred[all_pred <= 0.5] = 0
self.accuracy = metrics.accuracy_score(all_target, all_pred)
epoch_loss = epoch_loss / training_step
print('Epoch %d/%d, loss : %3.5f, auc : %3.5f, accuracy : %3.5f' % (epoch+1, self.args.num_epochs, epoch_loss, self.auc, self.accuracy))
self.write_log(epoch=epoch+1, auc=self.auc, accuracy=self.accuracy, loss=epoch_loss, name='training_')
valid_steps = valid_q_data.shape[0] // self.args.batch_size
valid_pred_list = list()
valid_target_list = list()
for s in range(valid_steps):
# Validation
valid_q = valid_q_data[s*self.args.batch_size:(s+1)*self.args.batch_size, :]
valid_qa = valid_qa_data[s*self.args.batch_size:(s+1)*self.args.batch_size, :]
# right : 1, wrong : 0, padding : -1
valid_target = (valid_qa - 1) // self.args.n_questions
valid_feed_dict = {self.q_data_seq : valid_q, self.qa_data_seq : valid_qa, self.target_seq : valid_target}
valid_loss, valid_pred = self.sess.run([self.loss, self.pred], feed_dict=valid_feed_dict)
# Same with training set
valid_right_target = np.asarray(valid_target).reshape(-1,)
valid_right_pred = np.asarray(valid_pred).reshape(-1,)
valid_right_index = np.flatnonzero(valid_right_target != -1).tolist()
valid_target_list.append(valid_right_target[valid_right_index])
valid_pred_list.append(valid_right_pred[valid_right_index])
all_valid_pred = np.concatenate(valid_pred_list, axis=0)
all_valid_target = np.concatenate(valid_target_list, axis=0)
valid_auc = metrics.roc_auc_score(all_valid_target, all_valid_pred)
# For validation accuracy
all_valid_pred[all_valid_pred > 0.5] = 1
all_valid_pred[all_valid_pred <= 0.5] = 0
valid_accuracy = metrics.accuracy_score(all_valid_target, all_valid_pred)
print('Epoch %d/%d, valid auc : %3.5f, valid accuracy : %3.5f' %(epoch+1, self.args.num_epochs, valid_auc, valid_accuracy))
# Valid log
self.write_log(epoch=epoch+1, auc=valid_auc, accuracy=valid_accuracy, loss=valid_loss, name='valid_')
if valid_auc > best_valid_auc:
print('%3.4f to %3.4f' % (best_valid_auc, valid_auc))
best_valid_auc = valid_auc
best_epoch = epoch + 1
self.save(best_epoch)
return best_epoch
def test(self, test_q, test_qa):
steps = test_q.shape[0] // self.args.batch_size
self.sess.run(tf.global_variables_initializer())
if self.load():
print('CKPT Loaded')
else:
raise Exception('CKPT need')
pred_list = list()
target_list = list()
for s in range(steps):
test_q_batch = test_q[s*self.args.batch_size:(s+1)*self.args.batch_size, :]
test_qa_batch = test_qa[s*self.args.batch_size:(s+1)*self.args.batch_size, :]
target = test_qa_batch[:,:]
target = target.astype(np.int)
target_batch = (target - 1) // self.args.n_questions
target_batch = target_batch.astype(np.float)
feed_dict = {self.q_data_seq:test_q_batch, self.qa_data_seq:test_qa_batch, self.target_seq:target_batch}
loss_, pred_ = self.sess.run([self.loss, self.pred], feed_dict=feed_dict)
# Get right answer index
# Make [batch size * seq_len, 1]
right_target = np.asarray(target_batch).reshape(-1,1)
right_pred = np.asarray(pred_).reshape(-1,1)
# np.flatnonzero returns indices which is nonzero, convert it list
right_index = np.flatnonzero(right_target != -1.).tolist()
# Number of 'training_step' elements list with [batch size * seq_len, ]
pred_list.append(right_pred[right_index])
target_list.append(right_target[right_index])
all_pred = np.concatenate(pred_list, axis=0)
all_target = np.concatenate(target_list, axis=0)
# Compute metrics
all_pred[all_pred > 0.5] = 1
all_pred[all_pred <= 0.5] = 0
self.test_auc = metrics.roc_auc_score(all_target, all_pred)
# Extract elements with boolean index
# Make '1' for elements higher than 0.5
# Make '0' for elements lower than 0.5
self.test_accuracy = metrics.accuracy_score(all_target, all_pred)
print('Test auc : %3.4f, Test accuracy : %3.4f' % (self.test_auc, self.test_accuracy))
@property
def model_dir(self):
return '{}_{}batch_{}epochs'.format(self.args.dataset, self.args.batch_size, self.args.num_epochs)
def load(self):
checkpoint_dir = os.path.join(self.args.checkpoint_dir, self.model_dir)
ckpt = tf.train.get_checkpoint_state(checkpoint_dir)
if ckpt and ckpt.model_checkpoint_path:
ckpt_name = os.path.basename(ckpt.model_checkpoint_path)
self.train_count = int(ckpt_name.split('-')[-1])
self.saver.restore(self.sess, os.path.join(checkpoint_dir, ckpt_name))
return True
else:
return False
def save(self, global_step):
model_name = 'DKVMN'
checkpoint_dir = os.path.join(self.args.checkpoint_dir, self.model_dir)
if not os.path.exists(checkpoint_dir):
os.mkdir(checkpoint_dir)
self.saver.save(self.sess, os.path.join(checkpoint_dir, model_name), global_step=global_step)
print('Save checkpoint at %d' % (global_step+1))
# Log file
def write_log(self, auc, accuracy, loss, epoch, name='training_'):
log_path = os.path.join(self.args.log_dir, name+self.model_dir+'.csv')
if not os.path.exists(log_path):
self.log_file = open(log_path, 'w')
self.log_file.write('Epoch\tAuc\tAccuracy\tloss\n')
else:
self.log_file = open(log_path, 'a')
self.log_file.write(str(epoch) + '\t' + str(auc) + '\t' + str(accuracy) + '\t' + str(loss) + '\n')
self.log_file.flush()
