def main():
parser = argparse.ArgumentParser(
description='Train and evaluate DigitNet to predict handwritten digits'
)
parser.add_argument('--epochs',
default=5,
type=int,
help='The number of epochs to run the model')
parser.add_argument(
'--model',
default='multilayer',
help=
'Specifies which model to run, available models are: simple, sigmoid, multilayer, convolutional'
)
args = parser.parse_args()
if args.model == 'simple':
model, data_transformer = simple()
elif args.model == 'sigmoid':
model, data_transformer = sigmoid()
elif args.model == 'multilayer':
model, data_transformer = multilayer()
elif args.model == 'convolutional':
model, data_transformer = convolutional()
print('Summary of model:')
print(model.summary())
mnist = mnistdata.read_data_sets("data", one_hot=True, reshape=False)
print("\n|---- TRAINING ----|")
batch_size = 100
training_images = data_transformer(mnist.train.images)
testing_images = data_transformer(mnist.test.images)
model.compile(optimizer='rmsprop',
loss='categorical_crossentropy',
metrics=['accuracy'])
model.fit(training_images,
mnist.train.labels,
epochs=args.epochs,
batch_size=batch_size)
print("\n|---- EVALUATING ----|")
score = model.evaluate(testing_images,
mnist.test.labels,
batch_size=batch_size)
print("Accuracy: ", "%.2f" % (score[1] * 100), "%")
return
# \x/x\x/x\x/x\x/x\x/ -- fully connected layer (softmax) W [784, 10] b[10]
# · · · · · · · · Y [batch, 10]
# The model is:
#
# Y = softmax( X * W + b)
# X: matrix for 100 grayscale images of 28x28 pixels, flattened (there are 100 images in a mini-batch)
# W: weight matrix with 784 lines and 10 columns
# b: bias vector with 10 dimensions
# +: add with broadcasting: adds the vector to each line of the matrix (numpy)
# softmax(matrix) applies softmax on each line
# softmax(line) applies an exp to each value then divides by the norm of the resulting line
# Y: output matrix with 100 lines and 10 columns
# Download images and labels into mnist.test (10K images+labels) and mnist.train (60K images+labels)
mnist = mnistdata.read_data_sets("data", one_hot=True, reshape=False)
# input X: 28x28 grayscale images, the first dimension (None) will index the images in the mini-batch
X = tf.placeholder(tf.float32, [None, 28, 28, 1])
# correct answers will go here
Y_ = tf.placeholder(tf.float32, [None, 10])
# weights W[784, 10] 784=28*28
W = tf.Variable(tf.zeros([784, 10]))
# biases b[10]
b = tf.Variable(tf.zeros([10]))
# flatten the images into a single line of pixels
# -1 in the shape definition means "the only possible dimension that will preserve the number of elements"
XX = tf.reshape(X, [-1, 784])
# The model
# neural network with 5 layers
#
# · · · · · · · · · · (input data, flattened pixels) X [batch, 784] # 784 = 28*28
# \x/x\x/x\x/x\x/x\x/ -- fully connected layer (relu+BN) W1 [784, 200] B1[200]
# · · · · · · · · · Y1 [batch, 200]
# \x/x\x/x\x/x\x/ -- fully connected layer (relu+BN) W2 [200, 100] B2[100]
# · · · · · · · Y2 [batch, 100]
# \x/x\x/x\x/ -- fully connected layer (relu+BN) W3 [100, 60] B3[60]
# · · · · · Y3 [batch, 60]
# \x/x\x/ -- fully connected layer (relu+BN) W4 [60, 30] B4[30]
# · · · Y4 [batch, 30]
# \x/ -- fully connected layer (softmax) W5 [30, 10] B5[10]
# · Y5 [batch, 10]
# Download images and labels into mnist.test (10K images+labels) and mnist.train (60K images+labels)
mnist = mnistdata.read_data_sets("data", one_hot=True, reshape=False)
# input X: 28x28 grayscale images, the first dimension (None) will index the images in the mini-batch
X = tf.placeholder(tf.float32, [None, 28, 28, 1])
# correct answers will go here
Y_ = tf.placeholder(tf.float32, [None, 10])
# variable learning rate
lr = tf.placeholder(tf.float32)
# train/test selector for batch normalisation
tst = tf.placeholder(tf.bool)
# training iteration
iter = tf.placeholder(tf.int32)
# five layers and their number of neurons (tha last layer has 10 softmax neurons)
L = 200
M = 100
def main():
print("Tensorflow version " + tf.__version__)
tf.set_random_seed(0)
mnist = mnistdata.read_data_sets("data", one_hot=True, reshape=False)
height = 28
width = 28
channels = 1
output = 10
minibatch_ph = None # Will be determined during runtime
minibatch = 100
X = tf.placeholder(tf.float32, [minibatch_ph, height, width, channels])
# NOTE: Y_ are correct answers
Y_ = tf.placeholder(tf.float32, [minibatch_ph, output])
W = tf.Variable(tf.zeros([height * width, output]))
b = tf.Variable(tf.zeros([output]))
# NOTE: Flatten
# -1 means: Use the dimension which fits
# In this case it will be minibatch*width
XX = tf.reshape(X, [-1, height * width])
Y = tf.nn.softmax(tf.matmul(XX, W) + b)
# cross-entropy = - sum( Y_i * log(Yi) )
# NOTE: We use mean to make things independent of batch size
# NOTE: This is value is connected to batch size and learning rate
# In the original solution this was multiplied with 1000
# (100 from the batch size, 10 from number of outputs),
# and the learning rate was reduced by 1000
cross_entropy = -tf.reduce_mean(Y_ * tf.log(Y))
train_step = \
tf.train.GradientDescentOptimizer(5).minimize(cross_entropy)
correct_prediction = tf.equal(tf.argmax(Y, 1), tf.argmax(Y_, 1))
accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))
# init
init = tf.global_variables_initializer()
sess = tf.Session()
sess.run(init)
for i in range(2000 + 1):
# Get the batches
batch_X, batch_Y = mnist.train.next_batch(minibatch)
# Training
if i % 50 == 0:
a, c = sess.run([accuracy, cross_entropy],
feed_dict={
X: batch_X,
Y_: batch_Y
})
print(str(i) + ": accuracy:" + str(a) + " loss: " + str(c))
# Test values
if i % 10 == 0:
a, c = sess.run([accuracy, cross_entropy],
feed_dict={
X: mnist.test.images,
Y_: mnist.test.labels
})
print(
str(i) + ": ********* epoch " +
str(i * minibatch // mnist.train.images.shape[0] + 1) +
" ********* test accuracy:" + str(a) + " test loss: " + str(c))
# Backprop
sess.run(train_step, feed_dict={X: batch_X, Y_: batch_Y})