Mercurial > ift6266
comparison scripts/stacked_dae.py @ 119:4f37755d301b
Refait stacked_dae.py en utilisant le dataset complet shared (juste reparti à 0 à partir du code du tutoriel), et préparé pour utiliser NIST (pas testé)
author | fsavard |
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date | Wed, 17 Feb 2010 17:06:54 -0500 |
parents | 0b4080394f2c |
children |
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118:0d083964af4b | 119:4f37755d301b |
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1 #!/usr/bin/python | 1 #!/usr/bin/python |
2 # coding: utf-8 | 2 # coding: utf-8 |
3 | 3 |
4 # Code for stacked denoising autoencoder | 4 import numpy |
5 # Tests with MNIST | 5 import theano |
6 # TODO: adapt for NIST | |
7 # Based almost entirely on deeplearning.net tutorial, modifications by | |
8 # François Savard | |
9 | |
10 # Base LogisticRegression, SigmoidalLayer, dA, SdA code taken | |
11 # from the deeplearning.net tutorial. Refactored a bit. | |
12 # Changes (mainly): | |
13 # - splitted initialization in smaller methods | |
14 # - removed the "givens" thing involving an index in the whole dataset | |
15 # (to allow flexibility in how data is inputted... not necessarily one big tensor) | |
16 # - changed the "driver" a lot, altough for the moment the same logic is used | |
17 | |
18 import time | 6 import time |
19 import theano | |
20 import theano.tensor as T | 7 import theano.tensor as T |
21 import theano.tensor.nnet | |
22 from theano.tensor.shared_randomstreams import RandomStreams | 8 from theano.tensor.shared_randomstreams import RandomStreams |
23 import numpy, numpy.random | 9 import os.path |
24 | 10 |
25 from pylearn.datasets import MNIST | 11 import gzip |
26 | 12 import cPickle |
13 | |
14 MNIST_LOCATION = '/u/savardf/datasets/mnist.pkl.gz' | |
27 | 15 |
28 # from pylearn codebase | 16 # from pylearn codebase |
29 def update_locals(obj, dct): | 17 def update_locals(obj, dct): |
30 if 'self' in dct: | 18 if 'self' in dct: |
31 del dct['self'] | 19 del dct['self'] |
32 obj.__dict__.update(dct) | 20 obj.__dict__.update(dct) |
33 | 21 |
34 | |
35 class LogisticRegression(object): | 22 class LogisticRegression(object): |
36 def __init__(self, input, n_in, n_out): | 23 def __init__(self, input, n_in, n_out): |
37 # initialize with 0 the weights W as a matrix of shape (n_in, n_out) | 24 # initialize with 0 the weights W as a matrix of shape (n_in, n_out) |
38 self.W = theano.shared(value=numpy.zeros((n_in,n_out), dtype = theano.config.floatX), | 25 self.W = theano.shared( value=numpy.zeros((n_in,n_out), |
39 name='W') | 26 dtype = theano.config.floatX) ) |
40 # initialize the baises b as a vector of n_out 0s | 27 # initialize the baises b as a vector of n_out 0s |
41 self.b = theano.shared(value=numpy.zeros((n_out,), dtype = theano.config.floatX), | 28 self.b = theano.shared( value=numpy.zeros((n_out,), |
42 name='b') | 29 dtype = theano.config.floatX) ) |
43 | |
44 # compute vector of class-membership probabilities in symbolic form | 30 # compute vector of class-membership probabilities in symbolic form |
45 self.p_y_given_x = T.nnet.softmax(T.dot(input, self.W)+self.b) | 31 self.p_y_given_x = T.nnet.softmax(T.dot(input, self.W)+self.b) |
46 | 32 |
47 # compute prediction as class whose probability is maximal in | 33 # compute prediction as class whose probability is maximal in |
48 # symbolic form | 34 # symbolic form |
49 self.y_pred=T.argmax(self.p_y_given_x, axis=1) | 35 self.y_pred=T.argmax(self.p_y_given_x, axis=1) |
50 | 36 |
37 # list of parameters for this layer | |
51 self.params = [self.W, self.b] | 38 self.params = [self.W, self.b] |
52 | 39 |
53 def negative_log_likelihood(self, y): | 40 def negative_log_likelihood(self, y): |
54 return -T.mean(T.log(self.p_y_given_x)[T.arange(y.shape[0]),y]) | 41 return -T.mean(T.log(self.p_y_given_x)[T.arange(y.shape[0]),y]) |
55 | 42 |
56 def errors(self, y): | 43 def errors(self, y): |
57 # check if y has same dimension of y_pred | 44 # check if y has same dimension of y_pred |
58 if y.ndim != self.y_pred.ndim: | 45 if y.ndim != self.y_pred.ndim: |
59 raise TypeError('y should have the same shape as self.y_pred', | 46 raise TypeError('y should have the same shape as self.y_pred', |
60 ('y', target.type, 'y_pred', self.y_pred.type)) | 47 ('y', target.type, 'y_pred', self.y_pred.type)) |
48 | |
61 # check if y is of the correct datatype | 49 # check if y is of the correct datatype |
62 if y.dtype.startswith('int'): | 50 if y.dtype.startswith('int'): |
63 # the T.neq operator returns a vector of 0s and 1s, where 1 | 51 # the T.neq operator returns a vector of 0s and 1s, where 1 |
64 # represents a mistake in prediction | 52 # represents a mistake in prediction |
65 return T.mean(T.neq(self.y_pred, y)) | 53 return T.mean(T.neq(self.y_pred, y)) |
82 | 70 |
83 self.output = T.nnet.sigmoid(T.dot(input, self.W) + self.b) | 71 self.output = T.nnet.sigmoid(T.dot(input, self.W) + self.b) |
84 self.params = [self.W, self.b] | 72 self.params = [self.W, self.b] |
85 | 73 |
86 | 74 |
75 | |
87 class dA(object): | 76 class dA(object): |
88 def __init__(self, n_visible= 784, n_hidden= 500, \ | 77 def __init__(self, n_visible= 784, n_hidden= 500, corruption_level = 0.1,\ |
89 corruption_level = 0.1, input = None, \ | 78 input = None, shared_W = None, shared_b = None): |
90 shared_W = None, shared_b = None): | 79 self.n_visible = n_visible |
91 update_locals(self, locals()) | 80 self.n_hidden = n_hidden |
92 | 81 |
93 self.init_randomizer() | 82 # create a Theano random generator that gives symbolic random values |
94 self.init_params() | 83 theano_rng = RandomStreams() |
95 self.init_functions() | 84 |
96 | 85 if shared_W != None and shared_b != None : |
97 def init_randomizer(self): | 86 self.W = shared_W |
98 # create a Theano random generator that gives symbolic random values | 87 self.b = shared_b |
99 self.theano_rng = RandomStreams() | 88 else: |
100 # create a numpy random generator | 89 # initial values for weights and biases |
101 self.numpy_rng = numpy.random.RandomState() | 90 # note : W' was written as `W_prime` and b' as `b_prime` |
102 | 91 |
103 def init_params(self): | 92 # W is initialized with `initial_W` which is uniformely sampled |
104 if self.shared_W != None and self.shared_b != None : | 93 # from -6./sqrt(n_visible+n_hidden) and 6./sqrt(n_hidden+n_visible) |
105 self.W = self.shared_W | 94 # the output of uniform if converted using asarray to dtype |
106 self.b = self.shared_b | 95 # theano.config.floatX so that the code is runable on GPU |
107 else: | 96 initial_W = numpy.asarray( numpy.random.uniform( \ |
108 # initial values for weights and biases | 97 low = -numpy.sqrt(6./(n_hidden+n_visible)), \ |
109 # note : W' was written as `W_prime` and b' as `b_prime` | 98 high = numpy.sqrt(6./(n_hidden+n_visible)), \ |
110 | 99 size = (n_visible, n_hidden)), dtype = theano.config.floatX) |
111 # W is initialized with `initial_W` which is uniformely sampled | 100 initial_b = numpy.zeros(n_hidden, dtype = theano.config.floatX) |
112 # from -6./sqrt(n_visible+n_hidden) and 6./sqrt(n_hidden+n_visible) | 101 |
113 # the output of uniform if converted using asarray to dtype | 102 |
114 # theano.config.floatX so that the code is runable on GPU | 103 # theano shared variables for weights and biases |
115 initial_W = numpy.asarray( self.numpy_rng.uniform( \ | 104 self.W = theano.shared(value = initial_W, name = "W") |
116 low = -numpy.sqrt(6./(n_hidden+n_visible)), \ | 105 self.b = theano.shared(value = initial_b, name = "b") |
117 high = numpy.sqrt(6./(n_hidden+n_visible)), \ | 106 |
118 size = (n_visible, n_hidden)), dtype = theano.config.floatX) | 107 |
119 initial_b = numpy.zeros(n_hidden) | 108 initial_b_prime= numpy.zeros(n_visible) |
120 | 109 # tied weights, therefore W_prime is W transpose |
121 # theano shared variables for weights and biases | 110 self.W_prime = self.W.T |
122 self.W = theano.shared(value = initial_W, name = "W") | 111 self.b_prime = theano.shared(value = initial_b_prime, name = "b'") |
123 self.b = theano.shared(value = initial_b, name = "b") | 112 |
124 | 113 # if no input is given, generate a variable representing the input |
125 initial_b_prime= numpy.zeros(self.n_visible) | 114 if input == None : |
126 # tied weights, therefore W_prime is W transpose | 115 # we use a matrix because we expect a minibatch of several examples, |
127 self.W_prime = self.W.T | 116 # each example being a row |
128 self.b_prime = theano.shared(value = initial_b_prime, name = "b'") | 117 self.x = T.dmatrix(name = 'input') |
129 | 118 else: |
130 def init_functions(self): | 119 self.x = input |
131 # if no input is given, generate a variable representing the input | 120 # Equation (1) |
132 if self.input == None : | 121 # keep 90% of the inputs the same and zero-out randomly selected subset of 10% of the inputs |
133 # we use a matrix because we expect a minibatch of several examples, | 122 # note : first argument of theano.rng.binomial is the shape(size) of |
134 # each example being a row | 123 # random numbers that it should produce |
135 self.x = T.dmatrix(name = 'input') | 124 # second argument is the number of trials |
136 else: | 125 # third argument is the probability of success of any trial |
137 self.x = self.input | 126 # |
138 | 127 # this will produce an array of 0s and 1s where 1 has a |
139 # keep 90% of the inputs the same and zero-out randomly selected subset of | 128 # probability of 1 - ``corruption_level`` and 0 with |
140 # 10% of the inputs | 129 # ``corruption_level`` |
141 # note : first argument of theano.rng.binomial is the shape(size) of | 130 self.tilde_x = theano_rng.binomial( self.x.shape, 1, 1 - corruption_level) * self.x |
142 # random numbers that it should produce | 131 # Equation (2) |
143 # second argument is the number of trials | 132 # note : y is stored as an attribute of the class so that it can be |
144 # third argument is the probability of success of any trial | 133 # used later when stacking dAs. |
145 # | 134 self.y = T.nnet.sigmoid(T.dot(self.tilde_x, self.W ) + self.b) |
146 # this will produce an array of 0s and 1s where 1 has a | 135 # Equation (3) |
147 # probability of 1 - ``corruption_level`` and 0 with | 136 self.z = T.nnet.sigmoid(T.dot(self.y, self.W_prime) + self.b_prime) |
148 # ``corruption_level`` | 137 # Equation (4) |
149 self.tilde_x = self.theano_rng.binomial(self.x.shape, 1, 1-self.corruption_level) * self.x | 138 # note : we sum over the size of a datapoint; if we are using minibatches, |
150 # using tied weights | 139 # L will be a vector, with one entry per example in minibatch |
151 self.y = T.nnet.sigmoid(T.dot(self.tilde_x, self.W) + self.b) | 140 self.L = - T.sum( self.x*T.log(self.z) + (1-self.x)*T.log(1-self.z), axis=1 ) |
152 self.z = T.nnet.sigmoid(T.dot(self.y, self.W_prime) + self.b_prime) | 141 # note : L is now a vector, where each element is the cross-entropy cost |
153 self.L = - T.sum( self.x*T.log(self.z) + (1-self.x)*T.log(1-self.z), axis=1 ) | 142 # of the reconstruction of the corresponding example of the |
154 # note : L is now a vector, where each element is the cross-entropy cost | 143 # minibatch. We need to compute the average of all these to get |
155 # of the reconstruction of the corresponding example of the | 144 # the cost of the minibatch |
156 # minibatch. We need to compute the average of all these to get | 145 self.cost = T.mean(self.L) |
157 # the cost of the minibatch | 146 |
158 self.cost = T.mean(self.L) | 147 self.params = [ self.W, self.b, self.b_prime ] |
159 | 148 |
160 self.params = [ self.W, self.b, self.b_prime ] | 149 |
161 | 150 |
162 class SdA(): | 151 |
163 def __init__(self, batch_size, n_ins, | 152 class SdA(object): |
164 hidden_layers_sizes, n_outs, | 153 def __init__(self, train_set_x, train_set_y, batch_size, n_ins, |
165 corruption_levels, rng, pretrain_lr, finetune_lr): | 154 hidden_layers_sizes, n_outs, |
166 update_locals(self, locals()) | 155 corruption_levels, rng, pretrain_lr, finetune_lr): |
167 | 156 |
168 self.layers = [] | 157 self.layers = [] |
169 self.pretrain_functions = [] | 158 self.pretrain_functions = [] |
170 self.params = [] | 159 self.params = [] |
171 self.n_layers = len(hidden_layers_sizes) | 160 self.n_layers = len(hidden_layers_sizes) |
172 | 161 |
173 if len(hidden_layers_sizes) < 1 : | 162 if len(hidden_layers_sizes) < 1 : |
174 raiseException (' You must have at least one hidden layer ') | 163 raiseException (' You must have at least one hidden layer ') |
175 | 164 |
165 | |
176 # allocate symbolic variables for the data | 166 # allocate symbolic variables for the data |
177 self.x = T.matrix('x') # the data is presented as rasterized images | 167 index = T.lscalar() # index to a [mini]batch |
178 self.y = T.ivector('y') # the labels are presented as 1D vector of | 168 self.x = T.matrix('x') # the data is presented as rasterized images |
179 # [int] labels | 169 self.y = T.ivector('y') # the labels are presented as 1D vector of |
180 | 170 # [int] labels |
181 self.create_layers() | 171 |
182 self.init_finetuning() | |
183 | |
184 def create_layers(self): | |
185 for i in xrange( self.n_layers ): | 172 for i in xrange( self.n_layers ): |
186 # construct the sigmoidal layer | 173 # construct the sigmoidal layer |
187 | 174 |
188 # the size of the input is either the number of hidden units of | 175 # the size of the input is either the number of hidden units of |
189 # the layer below or the input size if we are on the first layer | 176 # the layer below or the input size if we are on the first layer |
190 if i == 0 : | 177 if i == 0 : |
191 input_size = self.n_ins | 178 input_size = n_ins |
192 else: | 179 else: |
193 input_size = self.hidden_layers_sizes[i-1] | 180 input_size = hidden_layers_sizes[i-1] |
194 | 181 |
195 # the input to this layer is either the activation of the hidden | 182 # the input to this layer is either the activation of the hidden |
196 # layer below or the input of the SdA if you are on the first | 183 # layer below or the input of the SdA if you are on the first |
197 # layer | 184 # layer |
198 if i == 0 : | 185 if i == 0 : |
199 layer_input = self.x | 186 layer_input = self.x |
200 else: | 187 else: |
201 layer_input = self.layers[-1].output | 188 layer_input = self.layers[-1].output |
202 | 189 |
203 layer = SigmoidalLayer(self.rng, layer_input, input_size, | 190 layer = SigmoidalLayer(rng, layer_input, input_size, |
204 self.hidden_layers_sizes[i] ) | 191 hidden_layers_sizes[i] ) |
205 # add the layer to the | 192 # add the layer to the |
206 self.layers += [layer] | 193 self.layers += [layer] |
207 self.params += layer.params | 194 self.params += layer.params |
208 | 195 |
209 # Construct a denoising autoencoder that shared weights with this | 196 # Construct a denoising autoencoder that shared weights with this |
210 # layer | 197 # layer |
211 dA_layer = dA(input_size, self.hidden_layers_sizes[i], \ | 198 dA_layer = dA(input_size, hidden_layers_sizes[i], \ |
212 corruption_level = self.corruption_levels[0],\ | 199 corruption_level = corruption_levels[0],\ |
213 input = layer_input, \ | 200 input = layer_input, \ |
214 shared_W = layer.W, shared_b = layer.b) | 201 shared_W = layer.W, shared_b = layer.b) |
215 | 202 |
216 self.init_updates_for_layer(dA_layer) | 203 # Construct a function that trains this dA |
217 | 204 # compute gradients of layer parameters |
218 def init_updates_for_layer(self, dA_layer): | 205 gparams = T.grad(dA_layer.cost, dA_layer.params) |
219 # Construct a function that trains this dA | 206 # compute the list of updates |
220 # compute gradients of layer parameters | 207 updates = {} |
221 gparams = T.grad(dA_layer.cost, dA_layer.params) | 208 for param, gparam in zip(dA_layer.params, gparams): |
222 # compute the list of updates | 209 updates[param] = param - gparam * pretrain_lr |
223 updates = {} | 210 |
224 for param, gparam in zip(dA_layer.params, gparams): | 211 # create a function that trains the dA |
225 updates[param] = param - gparam * self.pretrain_lr | 212 update_fn = theano.function([index], dA_layer.cost, \ |
226 | 213 updates = updates, |
227 # create a function that trains the dA | 214 givens = { |
228 update_fn = theano.function([self.x], dA_layer.cost, \ | 215 self.x : train_set_x[index*batch_size:(index+1)*batch_size]}) |
229 updates = updates) | 216 # collect this function into a list |
230 | 217 self.pretrain_functions += [update_fn] |
231 # collect this function into a list | 218 |
232 self.pretrain_functions += [update_fn] | 219 |
233 | |
234 def init_finetuning(self): | |
235 # We now need to add a logistic layer on top of the MLP | 220 # We now need to add a logistic layer on top of the MLP |
236 self.logLayer = LogisticRegression(\ | 221 self.logLayer = LogisticRegression(\ |
237 input = self.layers[-1].output,\ | 222 input = self.layers[-1].output,\ |
238 n_in = self.hidden_layers_sizes[-1], n_out = self.n_outs) | 223 n_in = hidden_layers_sizes[-1], n_out = n_outs) |
239 | 224 |
240 self.params += self.logLayer.params | 225 self.params += self.logLayer.params |
241 # construct a function that implements one step of finetunining | 226 # construct a function that implements one step of finetunining |
242 | 227 |
243 # compute the cost, defined as the negative log likelihood | 228 # compute the cost, defined as the negative log likelihood |
244 cost = self.logLayer.negative_log_likelihood(self.y) | 229 cost = self.logLayer.negative_log_likelihood(self.y) |
245 # compute the gradients with respect to the model parameters | 230 # compute the gradients with respect to the model parameters |
246 gparams = T.grad(cost, self.params) | 231 gparams = T.grad(cost, self.params) |
247 # compute list of updates | 232 # compute list of updates |
248 updates = {} | 233 updates = {} |
249 for param,gparam in zip(self.params, gparams): | 234 for param,gparam in zip(self.params, gparams): |
250 updates[param] = param - gparam*self.finetune_lr | 235 updates[param] = param - gparam*finetune_lr |
251 | 236 |
252 self.finetune = theano.function([self.x, self.y], cost, | 237 self.finetune = theano.function([index], cost, |
253 updates = updates) | 238 updates = updates, |
239 givens = { | |
240 self.x : train_set_x[index*batch_size:(index+1)*batch_size], | |
241 self.y : train_set_y[index*batch_size:(index+1)*batch_size]} ) | |
254 | 242 |
255 # symbolic variable that points to the number of errors made on the | 243 # symbolic variable that points to the number of errors made on the |
256 # minibatch given by self.x and self.y | 244 # minibatch given by self.x and self.y |
257 | 245 |
258 self.errors = self.logLayer.errors(self.y) | 246 self.errors = self.logLayer.errors(self.y) |
259 | 247 |
260 class MnistIterators: | 248 class Hyperparameters: |
261 def __init__(self, minibatch_size): | 249 def __init__(self, dict): |
250 self.__dict__.update(dict) | |
251 | |
252 def sgd_optimization_mnist(learning_rate=0.1, pretraining_epochs = 2, \ | |
253 pretrain_lr = 0.1, training_epochs = 5, \ | |
254 dataset='mnist.pkl.gz'): | |
255 # Load the dataset | |
256 f = gzip.open(dataset,'rb') | |
257 # this gives us train, valid, test (each with .x, .y) | |
258 dataset = cPickle.load(f) | |
259 f.close() | |
260 | |
261 n_ins = 28*28 | |
262 n_outs = 10 | |
263 | |
264 hyperparameters = Hyperparameters({'finetuning_lr':learning_rate, | |
265 'pretraining_lr':pretrain_lr, | |
266 'pretraining_epochs_per_layer':pretraining_epochs, | |
267 'max_finetuning_epochs':training_epochs, | |
268 'hidden_layers_sizes':[1000,1000,1000], | |
269 'corruption_levels':[0.2,0.2,0.2], | |
270 'minibatch_size':20}) | |
271 | |
272 sgd_optimization(dataset, hyperparameters, n_ins, n_outs) | |
273 | |
274 class NIST: | |
275 def __init__(self, minibatch_size, basepath=='/data/lisa/data/nist/by_class/all'): | |
262 self.minibatch_size = minibatch_size | 276 self.minibatch_size = minibatch_size |
263 | 277 self.basepath = basepath |
264 self.mnist = MNIST.first_1k() | 278 |
265 | 279 self.train = [None, None] |
266 self.len_train = len(self.mnist.train.x) | 280 self.test = [None, None] |
267 self.len_valid = len(self.mnist.valid.x) | 281 |
268 self.len_test = len(self.mnist.test.x) | 282 self.load_train_test() |
269 | 283 |
270 def train_x_batches(self): | 284 self.valid = [None, None] |
271 idx = 0 | 285 self.split_train_valid() |
272 while idx < len(self.mnist.train.x): | 286 |
273 yield self.mnist.train.x[idx:idx+self.minibatch_size] | 287 def set_filenames(self): |
274 idx += self.minibatch_size | 288 self.train_files = ['all_train_data.ft', |
275 | 289 'all_train_labels.ft'] |
276 def train_xy_batches(self): | 290 |
277 idx = 0 | 291 self.test_files = ['all_test_data.ft', |
278 while idx < len(self.mnist.train.x): | 292 'all_test_labels.ft'] |
279 mb_x = self.mnist.train.x[idx:idx+self.minibatch_size] | 293 |
280 mb_y = self.mnist.train.y[idx:idx+self.minibatch_size] | 294 def load_train_test(self): |
281 yield mb_x, mb_y | 295 self.load_data_labels(self.train_files, self.train) |
282 idx += self.minibatch_size | 296 self.load_data_labels(self.test_files, self.test) |
283 | 297 |
284 def valid_xy_batches(self): | 298 def load_data_labels(self, filenames, pair): |
285 idx = 0 | 299 for i, fn in enumerate(filenames): |
286 while idx < len(self.mnist.valid.x): | 300 f = open(fn) |
287 mb_x = self.mnist.valid.x[idx:idx+self.minibatch_size] | 301 pair[i] = ft.read(os.path.join(self.base_path, fn)) |
288 mb_y = self.mnist.valid.y[idx:idx+self.minibatch_size] | 302 f.close() |
289 yield mb_x, mb_y | 303 |
290 idx += self.minibatch_size | 304 def split_train_valid(self): |
291 | 305 test_len = len(self.test[0]) |
292 | 306 |
293 class MnistTrainingDriver: | 307 new_train_x = self.train[0][:-test_len] |
294 def __init__(self, rng=numpy.random): | 308 new_train_y = self.train[1][:-test_len] |
295 self.rng = rng | 309 |
296 | 310 self.valid[0] = self.train[0][-test_len:] |
297 self.init_SdA() | 311 self.valid[1] = self.train[1][-test_len:] |
298 | 312 |
299 def init_SdA(self): | 313 self.train[0] = new_train_x |
300 # Hyperparam | 314 self.train[1] = new_train_y |
301 hidden_layers_sizes = [1000, 1000, 1000] | 315 |
302 n_outs = 10 | 316 def sgd_optimization_nist(dataset_dir='/data/lisa/data/nist'): |
303 corruption_levels = [0.2, 0.2, 0.2] | 317 pass |
304 minibatch_size = 10 | 318 |
305 pretrain_lr = 0.001 | 319 def sgd_optimization(dataset, hyperparameters, n_ins, n_outs): |
306 finetune_lr = 0.001 | 320 hp = hyperparameters |
307 | 321 |
308 update_locals(self, locals()) | 322 train_set, valid_set, test_set = dataset |
309 | 323 |
310 self.mnist = MnistIterators(minibatch_size) | 324 def shared_dataset(data_xy): |
311 | 325 data_x, data_y = data_xy |
312 # construct the stacked denoising autoencoder class | 326 shared_x = theano.shared(numpy.asarray(data_x, dtype=theano.config.floatX)) |
313 self.classifier = SdA( batch_size = minibatch_size, \ | 327 shared_y = theano.shared(numpy.asarray(data_y, dtype=theano.config.floatX)) |
314 n_ins=28*28, \ | 328 return shared_x, T.cast(shared_y, 'int32') |
315 hidden_layers_sizes = hidden_layers_sizes, \ | 329 |
316 n_outs=n_outs, \ | 330 test_set_x, test_set_y = shared_dataset(test_set) |
317 corruption_levels = corruption_levels,\ | 331 valid_set_x, valid_set_y = shared_dataset(valid_set) |
318 rng = self.rng,\ | 332 train_set_x, train_set_y = shared_dataset(train_set) |
319 pretrain_lr = pretrain_lr, \ | 333 |
320 finetune_lr = finetune_lr) | 334 # compute number of minibatches for training, validation and testing |
321 | 335 n_train_batches = train_set_x.value.shape[0] / hp.minibatch_size |
322 def compute_validation_error(self): | 336 n_valid_batches = valid_set_x.value.shape[0] / hp.minibatch_size |
323 validation_error = 0.0 | 337 n_test_batches = test_set_x.value.shape[0] / hp.minibatch_size |
324 | 338 |
325 count = 0 | 339 # allocate symbolic variables for the data |
326 for mb_x, mb_y in self.mnist.valid_xy_batches(): | 340 index = T.lscalar() # index to a [mini]batch |
327 validation_error += self.classifier.errors(mb_x, mb_y) | 341 |
328 count += 1 | 342 # construct the stacked denoising autoencoder class |
329 | 343 classifier = SdA( train_set_x=train_set_x, train_set_y = train_set_y,\ |
330 return float(validation_error) / count | 344 batch_size = hp.minibatch_size, n_ins= n_ins, \ |
331 | 345 hidden_layers_sizes = hp.hidden_layers_sizes, n_outs=10, \ |
332 def pretrain(self): | 346 corruption_levels = hp.corruption_levels,\ |
333 pretraining_epochs = 20 | 347 rng = numpy.random.RandomState(1234),\ |
334 | 348 pretrain_lr = hp.pretraining_lr, finetune_lr = hp.finetuning_lr ) |
335 for layer_idx, update_fn in enumerate(self.classifier.pretrain_functions): | 349 |
336 for epoch in xrange(pretraining_epochs): | 350 |
337 # go through the training set | 351 start_time = time.clock() |
338 cost_acc = 0.0 | 352 ## Pre-train layer-wise |
339 for i, mb_x in enumerate(self.mnist.train_x_batches()): | 353 for i in xrange(classifier.n_layers): |
340 cost_acc += update_fn(mb_x) | 354 # go through pretraining epochs |
341 | 355 for epoch in xrange(hp.pretraining_epochs_per_layer): |
342 if i % 100 == 0: | 356 # go through the training set |
343 print i, "avg err = ", cost_acc / 100.0 | 357 for batch_index in xrange(n_train_batches): |
344 cost_acc = 0.0 | 358 c = classifier.pretrain_functions[i](batch_index) |
345 print 'Pre-training layer %d, epoch %d' % (layer_idx, epoch) | 359 print 'Pre-training layer %i, epoch %d, cost '%(i,epoch),c |
346 | 360 |
347 def finetune(self): | 361 end_time = time.clock() |
348 max_training_epochs = 1000 | 362 |
349 | 363 print ('Pretraining took %f minutes' %((end_time-start_time)/60.)) |
350 n_train_batches = self.mnist.len_train / self.minibatch_size | 364 # Fine-tune the entire model |
351 | 365 |
352 # early-stopping parameters | 366 minibatch_size = hp.minibatch_size |
353 patience = 10000 # look as this many examples regardless | 367 |
354 patience_increase = 2. # wait this much longer when a new best is | 368 # create a function to compute the mistakes that are made by the model |
355 # found | 369 # on the validation set, or testing set |
356 improvement_threshold = 0.995 # a relative improvement of this much is | 370 test_model = theano.function([index], classifier.errors, |
357 # considered significant | 371 givens = { |
358 validation_frequency = min(n_train_batches, patience/2) | 372 classifier.x: test_set_x[index*minibatch_size:(index+1)*minibatch_size], |
359 # go through this many | 373 classifier.y: test_set_y[index*minibatch_size:(index+1)*minibatch_size]}) |
360 # minibatche before checking the network | 374 |
361 # on the validation set; in this case we | 375 validate_model = theano.function([index], classifier.errors, |
362 # check every epoch | 376 givens = { |
363 | 377 classifier.x: valid_set_x[index*minibatch_size:(index+1)*minibatch_size], |
364 | 378 classifier.y: valid_set_y[index*minibatch_size:(index+1)*minibatch_size]}) |
365 # TODO: use this | 379 |
366 best_params = None | 380 |
367 best_validation_loss = float('inf') | 381 # early-stopping parameters |
368 test_score = 0. | 382 patience = 10000 # look as this many examples regardless |
369 start_time = time.clock() | 383 patience_increase = 2. # wait this much longer when a new best is |
370 | 384 # found |
371 done_looping = False | 385 improvement_threshold = 0.995 # a relative improvement of this much is |
372 epoch = 0 | 386 # considered significant |
373 | 387 validation_frequency = min(n_train_batches, patience/2) |
374 while (epoch < max_training_epochs) and (not done_looping): | 388 # go through this many |
375 epoch = epoch + 1 | 389 # minibatche before checking the network |
376 for minibatch_index, (mb_x, mb_y) in enumerate(self.mnist.train_xy_batches()): | 390 # on the validation set; in this case we |
377 cost_ij = classifier.finetune(mb_x, mb_y) | 391 # check every epoch |
378 iter = epoch * n_train_batches + minibatch_index | 392 |
379 | 393 best_params = None |
380 if (iter+1) % validation_frequency == 0: | 394 best_validation_loss = float('inf') |
381 this_validation_loss = self.compute_validation_error() | 395 test_score = 0. |
382 print('epoch %i, minibatch %i/%i, validation error %f %%' % \ | 396 start_time = time.clock() |
383 (epoch, minibatch_index+1, n_train_batches, \ | 397 |
384 this_validation_loss*100.)) | 398 done_looping = False |
385 | 399 epoch = 0 |
386 # if we got the best validation score until now | 400 |
387 if this_validation_loss < best_validation_loss: | 401 while (epoch < hp.max_finetuning_epochs) and (not done_looping): |
388 | 402 epoch = epoch + 1 |
389 #improve patience if loss improvement is good enough | 403 for minibatch_index in xrange(n_train_batches): |
390 if this_validation_loss < best_validation_loss * \ | 404 |
391 improvement_threshold : | 405 cost_ij = classifier.finetune(minibatch_index) |
392 patience = max(patience, iter * patience_increase) | 406 iter = epoch * n_train_batches + minibatch_index |
393 print "Improving patience" | 407 |
394 | 408 if (iter+1) % validation_frequency == 0: |
395 # save best validation score and iteration number | 409 |
396 best_validation_loss = this_validation_loss | 410 validation_losses = [validate_model(i) for i in xrange(n_valid_batches)] |
397 best_iter = iter | 411 this_validation_loss = numpy.mean(validation_losses) |
398 | 412 print('epoch %i, minibatch %i/%i, validation error %f %%' % \ |
399 # test it on the test set | 413 (epoch, minibatch_index+1, n_train_batches, \ |
400 #test_losses = [test_model(i) for i in xrange(n_test_batches)] | 414 this_validation_loss*100.)) |
401 #test_score = numpy.mean(test_losses) | 415 |
402 #print((' epoch %i, minibatch %i/%i, test error of best ' | 416 |
403 # 'model %f %%') % | 417 # if we got the best validation score until now |
404 # (epoch, minibatch_index+1, n_train_batches, | 418 if this_validation_loss < best_validation_loss: |
405 # test_score*100.)) | 419 |
406 | 420 #improve patience if loss improvement is good enough |
407 | 421 if this_validation_loss < best_validation_loss * \ |
408 if patience <= iter : | 422 improvement_threshold : |
423 patience = max(patience, iter * patience_increase) | |
424 | |
425 # save best validation score and iteration number | |
426 best_validation_loss = this_validation_loss | |
427 best_iter = iter | |
428 | |
429 # test it on the test set | |
430 test_losses = [test_model(i) for i in xrange(n_test_batches)] | |
431 test_score = numpy.mean(test_losses) | |
432 print((' epoch %i, minibatch %i/%i, test error of best ' | |
433 'model %f %%') % | |
434 (epoch, minibatch_index+1, n_train_batches, | |
435 test_score*100.)) | |
436 | |
437 | |
438 if patience <= iter : | |
409 done_looping = True | 439 done_looping = True |
410 break | 440 break |
411 | 441 |
412 def train(): | |
413 driver = MnistTrainingDriver() | |
414 start_time = time.clock() | |
415 driver.pretrain() | |
416 print "PRETRAINING DONE. STARTING FINETUNING." | |
417 driver.finetune() | |
418 end_time = time.clock() | 442 end_time = time.clock() |
443 print(('Optimization complete with best validation score of %f %%,' | |
444 'with test performance %f %%') % | |
445 (best_validation_loss * 100., test_score*100.)) | |
446 print ('The code ran for %f minutes' % ((end_time-start_time)/60.)) | |
447 | |
419 | 448 |
420 if __name__ == '__main__': | 449 if __name__ == '__main__': |
421 train() | 450 import sys |
422 | 451 args = sys.argv[1:] |
452 if len(args) > 0 and args[0] == "jobman_add": | |
453 jobman_add() | |
454 else: | |
455 sgd_optimization_mnist(dataset=MNIST_LOCATION) | |
456 |