def task(self):
listInst = load_training_9k(10)
net = nn.init_net([14*14,15,10])
listDblResult = list(build_and_measure_net(
net, listInst, listInst, nn.distributed_encode_label,
nn.distributed_decode_net_output, self.LEARNING_RATE,
self.ROUNDS))
return performance_graph([[a for a,_ in listDblResult]],
"Digit Recognition Training Accuracy")
def learn_xor():
"""Build a neural network which solves XOR."""
net = nn.init_net([2, 2, 1])
for _ in xrange(5000):
for inst in XOR_INSTANCES:
nn.update_net(net, inst, 0.5, [inst.iLabel])
for inst in XOR_INSTANCES:
print inst.iLabel, nn.feed_forward(net, inst.listDblFeatures)
nn.print_net(net)
def task(self):
listInst = load_training_9k(10)
net = nn.init_net([14*14,15,10])
listDblResult = list(build_and_measure_net(
net, listInst, listInst, nn.distributed_encode_label,
nn.distributed_decode_net_output, self.LEARNING_RATE,
self.ROUNDS))
return performance_graph([[a for a,_ in listDblResult]],
"Digit Recognition Training Accuracy")
def build_xor_net():
HIDDEN_NODES = 2
ROUNDS = 5000
assert XOR_INSTANCES
net = nn.init_net([2, HIDDEN_NODES, 1], 0.001)
for ixRound in xrange(ROUNDS):
dblAlpha = 2.0 * ROUNDS / (ixRound + ROUNDS)
for inst in XOR_INSTANCES:
nn.update_net(net, inst, dblAlpha, [inst.iLabel])
return net
def build_xor_net():
HIDDEN_NODES = 2
ROUNDS = 5000
LEARNING_RATE = 0.35
assert XOR_INSTANCES
net = nn.init_net([2, HIDDEN_NODES, 1], 0.001)
for ixRound in xrange(ROUNDS):
dblAlpha = 2.0 * ROUNDS / (ixRound + ROUNDS)
for inst in XOR_INSTANCES:
nn.update_net(net, inst, dblAlpha, [inst.iLabel])
return net
def measure_performance(self, fxnEncode, fxnDecode):
listInstTraining = load_training_9k(self.TRAINING_INSTANCES)
listInstTest = load_test_1k(self.TEST_INSTANCES)
net = nn.init_net(self.NETWORK_CONFIGURATION)
listDblResult = list(build_and_measure_net(
net,listInstTraining,listInstTest, fxnEncode, fxnDecode,
self.LEARNING_RATE, self.ROUNDS))
listDblTest = [a for a,_ in listDblResult]
listDblTrain = [b for _,b in listDblResult]
sTitle = ("Digit Recognition Test Accuracy Trained on %d Instances"
% len(listInstTraining))
return performance_graph([listDblTest,listDblTrain], sTitle)
def test_update_net(self):
# Test a simple network to make sure that forward and backprop are
# working properly.
# 2 inputs, 2 hidden nodes, 1 output node
net = nn.init_net([2, 2, 1])
# Set the weights on the first hidden node to 0.1, the weights on the
# second hidden node to -0.1.
def init_weights(p, input_weight, w0):
for i in xrange(len(p.listDblW)):
p.listDblW[i] = input_weight
p.dblW0 = w0
# Weights for the first hidden node to be 0.1
init_weights(net.listLayer[0].listPcpt[0], 0.1, 0.0)
# Weights for the second hidden node to be -0.1
init_weights(net.listLayer[0].listPcpt[1], -0.1, 0.0)
# Weights for the output layer to be 0.1
init_weights(net.listLayer[1].listPcpt[0], 1.0, 0.0)
# Inputs are 1 and -1
inst = nn.Instance(0, [1.0, -0.9])
# Target output is 0.5
targets = [0.5]
# The output of hidden unit 1 will be 1 / (1 + e^(-0.01))
# The output of hidden unit 2 will be 1 / (1 + e^(0.01))
# The inputs to the output unit will be 1.0, leading to output 0.731
# The error at the output will be -0.231
nn.update_net(net, inst, 1.0, targets)
def get_weight(layer_id, perceptron_id, input_id):
if input_id == -1:
return net.listLayer[layer_id].listPcpt[perceptron_id].dblW0
return net.listLayer[layer_id].listPcpt[perceptron_id].listDblW[input_id]
output = 1.0 / (1.0 + math.exp(-1.0))
delta_out = (0.5 - output) * output * (1 - output)
h1_out = 1.0 / (1.0 + math.exp(-0.01))
h2_out = 1.0 / (1.0 + math.exp(0.01))
self.assertAlmostEqual(1.0 + 1.0 * h1_out * delta_out, get_weight(1, 0, 0))
self.assertAlmostEqual(1.0 + 1.0 * h2_out * delta_out, get_weight(1, 0, 1))
self.assertAlmostEqual(1.0 * 1.0 * delta_out, get_weight(1, 0, -1))
in1 = 1.0 / (1.0 + math.exp(-0.01))
delta_hidden1 = in1 * (1 - in1) * delta_out
# For the hidden units, in is 0, so no weight updates should occur.
self.assertAlmostEqual(0.1 + 1.0 * delta_hidden1, get_weight(0, 0, 0))
self.assertAlmostEqual(0.1 - 0.9 * delta_hidden1, get_weight(0, 0, 1))
self.assertAlmostEqual(delta_hidden1, get_weight(0, 0, -1))
in2 = 1.0 / (1.0 + math.exp(0.01))
delta_hidden2 = in2 * (1 - in2) * delta_out
self.assertAlmostEqual(-0.1 + 1.0 * delta_hidden2, get_weight(0, 1, 0))
self.assertAlmostEqual(-0.1 - 0.9 * delta_hidden2, get_weight(0, 1, 1))
self.assertAlmostEqual(delta_hidden2, get_weight(0, 0, -1))
def test_update_net(self):
# Test a simple network to make sure that forward and backprop are
# working properly.
# 2 inputs, 2 hidden nodes, 1 output node
net = nn.init_net([2, 2, 1])
# Set the weights on the first hidden node to 0.1, the weights on the
# second hidden node to -0.1.
def init_weights(p, input_weight, w0):
for i in xrange(len(p.listDblW)):
p.listDblW[i] = input_weight
p.dblW0 = w0
# Weights for the first hidden node to be 0.1
init_weights(net.listLayer[0].listPcpt[0], 0.1, 0.0)
# Weights for the second hidden node to be -0.1
init_weights(net.listLayer[0].listPcpt[1], -0.1, 0.0)
# Weights for the output layer to be 0.1
init_weights(net.listLayer[1].listPcpt[0], 1.0, 0.0)
# Inputs are 1 and -1
inst = nn.Instance(0, [ 1.0, -0.9 ])
# Target output is 0.5
targets = [ 0.5 ]
# The output of hidden unit 1 will be 1 / (1 + e^(-0.01))
# The output of hidden unit 2 will be 1 / (1 + e^(0.01))
# The inputs to the output unit will be 1.0, leading to output 0.731
# The error at the output will be -0.231
nn.update_net(net, inst, 1.0, targets)
def get_weight(layer_id, perceptron_id, input_id):
if input_id == -1:
return net.listLayer[layer_id].listPcpt[perceptron_id].dblW0
return net.listLayer[layer_id].listPcpt[perceptron_id].listDblW[input_id]
output = 1.0 / (1.0 + math.exp(-1.0))
delta_out = (0.5 - output) * output * (1 - output)
h1_out = 1.0 / (1.0 + math.exp(-.01))
h2_out = 1.0 / (1.0 + math.exp(.01))
self.assertAlmostEqual(1.0 + 1.0 * h1_out * delta_out, get_weight(1, 0, 0))
self.assertAlmostEqual(1.0 + 1.0 * h2_out * delta_out, get_weight(1, 0, 1))
self.assertAlmostEqual(1.0 * 1.0 * delta_out, get_weight(1, 0, -1))
in1 = 1.0 / (1.0 + math.exp(-0.01))
delta_hidden1 = in1 * (1 - in1) * delta_out
# For the hidden units, in is 0, so no weight updates should occur.
self.assertAlmostEqual(0.1 + 1.0 * delta_hidden1, get_weight(0, 0, 0))
self.assertAlmostEqual(0.1 - 0.9 * delta_hidden1, get_weight(0, 0, 1))
self.assertAlmostEqual(delta_hidden1, get_weight(0, 0, -1))
in2 = 1.0 / (1.0 + math.exp(0.01))
delta_hidden2 = in2 * (1 - in2) * delta_out
self.assertAlmostEqual(-0.1 + 1.0 * delta_hidden2,
get_weight(0, 1, 0))
self.assertAlmostEqual(-0.1 - 0.9 * delta_hidden2,
get_weight(0, 1, 1))
self.assertAlmostEqual(delta_hidden2, get_weight(0, 0, -1))
def measure_performance(self, fxnEncode, fxnDecode):
listInstTraining = load_training_9k(self.TRAINING_INSTANCES)
listInstTest = load_test_1k(self.TEST_INSTANCES)
net = nn.init_net(self.NETWORK_CONFIGURATION)
listDblResult = list(build_and_measure_net(
net,listInstTraining,listInstTest, fxnEncode, fxnDecode,
self.LEARNING_RATE, self.ROUNDS))
listDblTest = [a for a,_ in listDblResult]
listDblTrain = [b for _,b in listDblResult]
sTitle = ("Digit Recognition Test Accuracy Trained on %d Instances"
% len(listInstTraining))
return performance_graph([listDblTest,listDblTrain], sTitle)
def learn_nn_classifier(listCLayerSize, lstTrainBoostInst, fxnEncode, fxnDecode):
"""Given the test data set of BoostInstances, learns and
returns the learned neural net.
net = nn.init_net([2,2,1])
learn_nn_classifier(net, XOR_INSTANCES, nn.binary_encode_label,
nn.binary_decode_net_output)
Learning rate: 1.923447Round 200 complete. Training Accuracy: 0.250000
Learning rate: 1.905125Round 250 complete. Training Accuracy: 0.750000
Learning rate: 1.887149Round 300 complete. Training Accuracy: 0.750000
Learning rate: 1.869508Round 350 complete. Training Accuracy: 0.750000
Learning rate: 1.852195Round 400 complete. Training Accuracy: 1.000000
Out[99]: <nn.NeuralNet at 0x9504950>
"""
# learn through rounds number of epochs
rounds = 500
interval = 50
stopRound = 350
iInst = len(lstTrainBoostInst)
net = nn.init_net(listCLayerSize)
for ixRound in xrange(rounds):
dblAlpha = 2.0*rounds/(ixRound + rounds)
# learn through one epoch and compute the error
errors = 0
for boostInst in lstTrainBoostInst:
inst = nn.Instance(boostInst.iLabel, boostInst.listAttrs)
listDblOut = nn.update_net(net, inst, dblAlpha, fxnEncode(inst.iLabel))
iGuess = fxnDecode(listDblOut)
if iGuess != inst.iLabel:
errors += 1
# print result after an interval of rounds
if not((ixRound+1) % interval):
sys.stderr.write('Learning rate: %f ' % dblAlpha)
sys.stderr.write("Epoch: %d Training Accuracy: %f \n" % (ixRound + 1,
1 - errors * 1.0 / iInst))
# implement a stopping condition.
if (ixRound+1) == stopRound:
return net
return net
def test_init_net(self):
layer_sizes = [3, 2, 1]
neural_net = nn.init_net(layer_sizes)
self.assertEqual(2, len(neural_net.listLayer))
# Make sure that the layers are configured correctly.
layer0 = neural_net.listLayer[0]
self.assertEqual(3, layer0.layer_input_size())
self.assertEqual(2, layer0.layer_output_size())
def check_perceptrons(layer, num_inputs):
for p in layer.listPcpt:
for w in p.listDblW:
self.assertTrue(w >= -0.1 and w <= 0.1)
self.assertTrue(p.dblW0 >= -0.1 and p.dblW0 <= 0.1)
self.assertEqual(num_inputs, len(p.listDblW))
check_perceptrons(layer0, 3)
# Weights on all inputs should be between -0.1 and 0.1
layer1 = neural_net.listLayer[1]
self.assertEqual(2, layer1.layer_input_size())
self.assertEqual(1, layer1.layer_output_size())
check_perceptrons(layer1, 2)
def test_init_net(self):
layer_sizes = [3, 2, 1]
neural_net = nn.init_net(layer_sizes)
self.assertEqual(2, len(neural_net.listLayer))
# Make sure that the layers are configured correctly.
layer0 = neural_net.listLayer[0]
self.assertEqual(3, layer0.layer_input_size())
self.assertEqual(2, layer0.layer_output_size())
def check_perceptrons(layer, num_inputs):
for p in layer.listPcpt:
for w in p.listDblW:
self.assertTrue(w >= -0.1 and w <= 0.1)
self.assertTrue(p.dblW0 >= -0.1 and p.dblW0 <= 0.1)
self.assertEqual(num_inputs, len(p.listDblW))
check_perceptrons(layer0, 3)
# Weights on all inputs should be between -0.1 and 0.1
layer1 = neural_net.listLayer[1]
self.assertEqual(2, layer1.layer_input_size())
self.assertEqual(1, layer1.layer_output_size())
check_perceptrons(layer1, 2)
def experiment(opts):
"""Run a neural net experiment."""
dictSeen = {}
writer = csv.writer(open("500epochs_80Nodes_4.csv", "wb"))
def load(sAttrFilename, sClassFilename):
if sAttrFilename in dictSeen:
return dictSeen[sAttrFilename]
sys.stderr.write("Loading %s and %s..." %
(sAttrFilename, sClassFilename))
listInst = load_separate_data(sAttrFilename, sClassFilename,
opts.max_inst)
sys.stderr.write("done.\n")
dictSeen[sAttrFilename] = listInst
return listInst
listInstTrain = load(opts.attrtrain, opts.classtrain)
listInstVal = load(opts.attrvalidation, opts.classvalidation)
listInstTest = load(opts.attrtest, opts.classtest)
config = [opts.num_inputs]
if opts.hidden_units:
print 'Adding a hidden layer with %d units' % opts.hidden_units
config.append(opts.hidden_units)
config.append(7) #Covertype data set
#config.append(10)
#config.append(4)
dblPrevAccuracy = 0.0
dblCurAccuracy = 0.0
dblStopDeltaAccuracy = 0.05
iEpochInterval = 5
net = nn.init_net(config)
for ixRound in xrange(opts.rounds):
dblAlpha = 2.0 * opts.rounds / (ixRound + opts.rounds)
print 'Learning rate: %f' % dblAlpha
# Count error
errors = 0
for inst in listInstTrain:
listDblOut = nn.update_net(
net, inst, dblAlpha, nn.distributed_encode_label(inst.iLabel))
iGuess = nn.distributed_decode_net_output(listDblOut)
if iGuess != inst.iLabel:
errors += 1
# Compute validation error
validation_correct = num_correct(net, listInstVal,
nn.distributed_decode_net_output)
sys.stderr.write(
"Round %d complete. Training Accuracy: %f, Validation Accuracy: %f\n"
% (ixRound + 1, 1 - errors * 1.0 / len(listInstTrain),
validation_correct * 1.0 / len(listInstVal)))
# RECORDING
writer.writerow([
ixRound + 1, dblAlpha, 1 - errors * 1.0 / len(listInstTrain),
validation_correct * 1.0 / len(listInstVal)
])
if opts.stopping_condition:
if (ixRound + 1) % iEpochInterval is 0:
dblCurAccuracy = validation_correct * 1.0 / len(listInstVal)
if (dblCurAccuracy - dblPrevAccuracy) < dblStopDeltaAccuracy:
break
else:
dblPrevAccuracy = dblCurAccuracy
cCorrect = 0
for inst in listInstTest:
listDblOut = nn.feed_forward(net, inst.listDblFeatures)
iGuess = nn.distributed_decode_net_output(listDblOut)
cCorrect += int(inst.iLabel == iGuess)
print "correct:", cCorrect, "out of", len(listInstTest),
print "(%.1f%%)" % (100.0 * cCorrect / len(listInstTest))
