def __init__(self):
# Define inputs
input_var = T.ftensor4('input_var') # input images (batchx3x64x64)
labels_classifier_var = T.ivector('labels_classifier_var') # labels for images
labels_domain_var = T.ivector('labels_domain_var') # labels for domain (1 for source, 0 for target)
learning_rate = T.fscalar('learning_rate')
# Define classifier networks
network_classifier = self.network_classifier(input_var)
network_discriminator = self.network_discriminator(network_classifier['classifier/pool1'])
# Define outputs
prediction_classifier = get_output(network_classifier['classifier/output']) # prob image classification
prediction_discriminator = get_output(network_discriminator['discriminator/output']) # prob image domain (should be 1 for source)
# Define losses (objectives)
loss_classifier_only = T.mean(categorical_crossentropy(prediction_classifier, labels_classifier_var) * labels_domain_var)
loss_discriminator = T.mean(categorical_crossentropy(prediction_discriminator, labels_domain_var))
loss_classifier = loss_classifier_only - loss_discriminator
# Define performance
perf_classifier_only = categorical_accuracy(prediction_classifier, labels_classifier_var).mean()
perf_discriminator = categorical_accuracy(prediction_discriminator, labels_domain_var).mean()
# Define params
params_classifier = lasagne.layers.get_all_params(network_classifier['classifier/output'], trainable=True)
params_discriminator = lasagne.layers.get_all_params(network_discriminator['discriminator/output'], trainable=True)
params_discriminator = [param for param in params_discriminator if 'discriminator' in param.name]
# Define updates
updates_classifier = lasagne.updates.adam(loss_classifier, params_classifier, learning_rate=learning_rate)
updates_classifier_only = lasagne.updates.adam(loss_classifier_only, params_classifier, learning_rate=learning_rate)
updates_discriminator = lasagne.updates.adam(loss_discriminator, params_discriminator, learning_rate=learning_rate)
# Define training functions
self.train_fn_classifier = theano.function(
[input_var, labels_classifier_var, labels_domain_var, learning_rate],
[loss_classifier, loss_classifier_only, prediction_classifier],
updates=updates_classifier)
self.train_fn_classifier_only = theano.function(
[input_var, labels_classifier_var, labels_domain_var, learning_rate],
[loss_classifier, loss_classifier_only, prediction_classifier],
updates=updates_classifier_only)
self.train_fn_discriminator = theano.function(
[input_var, labels_domain_var, learning_rate],
[loss_discriminator, prediction_discriminator],
updates=updates_discriminator)
# Define validation functions
self.valid_fn_classifier = theano.function(
[input_var, labels_classifier_var],
[perf_classifier_only, prediction_classifier])
self.valid_fn_discriminator = theano.function(
[input_var, labels_domain_var],
[perf_discriminator, prediction_discriminator])
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