Ejemplo n.º 1
0
def test_mlp_use_bias_pushed_when_not_explicitly_specified():
    mlp = MLP(activations=[Tanh(), Tanh(), None],
              dims=[4, 5, 6, 7],
              prototype=Linear(use_bias=False),
              use_bias=True)
    mlp.push_allocation_config()
    assert [lin.use_bias for lin in mlp.linear_transformations]
Ejemplo n.º 2
0
def test_mlp_use_bias_not_pushed_when_not_explicitly_specified():
    mlp = MLP(activations=[Tanh(), Tanh(), None],
              dims=[4, 5, 6, 7], prototype=Linear(use_bias=False))
    mlp.push_allocation_config()
    assert [not lin.use_bias for lin in mlp.linear_transformations]
def build_submodel(image_size,
                   num_channels,
                   L_dim_conv_layers,
                   L_filter_size,
                   L_pool_size,
                   L_activation_conv,
                   L_dim_full_layers,
                   L_activation_full,
                   dropout,
                   prediction,
                   allow_comment=False,
                   sub_dropout=0,
                   L_pool_step=[],
                   L_pool_padding=[]):

    # CONVOLUTION
    params_channels = [10**(-i) for i in range(len(L_dim_conv_layers) + 1)]
    index_params = 0
    params_channels.reverse()
    output_dim = num_channels * np.prod(image_size)
    conv_layers = []
    assert len(L_dim_conv_layers) == len(L_filter_size)
    assert len(L_dim_conv_layers) == len(L_pool_size)
    assert len(L_dim_conv_layers) == len(L_activation_conv)
    if len(L_pool_step) == 0:
        L_pool_step = [(1, 1) for i in range(len(L_dim_conv_layers))]
        L_pool_padding = [(0, 0) for i in range(len(L_dim_conv_layers))]
    assert len(L_dim_conv_layers) == len(L_pool_step)
    assert len(L_dim_conv_layers) == len(L_pool_padding)
    L_conv_dropout = [dropout] * len(
        L_dim_conv_layers)  # unique value of dropout for now
    convnet = None
    mlp = None
    if len(L_dim_conv_layers):
        for (num_filters, filter_size, pool_size, activation_str, dropout,
             index, step, padding) in zip(L_dim_conv_layers, L_filter_size,
                                          L_pool_size, L_activation_conv,
                                          L_conv_dropout,
                                          xrange(len(L_dim_conv_layers)),
                                          L_pool_step, L_pool_padding):

            # convert filter_size and pool_size in tuple
            filter_size = tuple(filter_size)

            if pool_size is None:
                pool_size = (0, 0)
            else:
                pool_size = tuple(pool_size)

            # TO DO : leaky relu
            if activation_str.lower() == 'rectifier':
                activation = Rectifier()
            elif activation_str.lower() == 'tanh':
                activation = Tanh()
            elif activation_str.lower() in ['sigmoid', 'logistic']:
                activation = Logistic()
            elif activation_str.lower() in ['id', 'identity']:
                activation = Identity()
            else:
                raise Exception("unknown activation function : %s",
                                activation_str)

            assert 0.0 <= dropout and dropout < 1.0
            num_filters = num_filters - int(num_filters * dropout)

            layer_conv = Convolutional(filter_size=filter_size,
                                       num_filters=num_filters,
                                       name="layer_%d" % index,
                                       weights_init=IsotropicGaussian(0.01),
                                       biases_init=Constant(0.0))
            conv_layers.append(layer_conv)
            conv_layers.append(activation)
            index_params += 1
            if not (pool_size[0] == 0 and pool_size[1] == 0):
                #pool = MaxPooling(pooling_size=pool_size, step=step, padding=padding)
                pool = MaxPooling(pooling_size=pool_size)
                conv_layers.append(pool)

        convnet = ConvolutionalSequence(conv_layers,
                                        num_channels=num_channels,
                                        image_size=image_size,
                                        name="conv_section")
        convnet.push_allocation_config()
        convnet.initialize()
        output_dim = np.prod(convnet.get_dim('output'))

    # MLP
    assert len(L_dim_full_layers) == len(L_activation_full)
    L_full_dropout = [dropout] * len(
        L_dim_full_layers)  # unique value of dropout for now

    # reguarding the batch dropout : the dropout is applied on the filter
    # which is equivalent to the output dimension
    # you have to look at the dropout_rate of the next layer
    # that is why we throw away the first value of L_exo_dropout_full_layers
    pre_dim = output_dim
    if allow_comment:
        print "When constructing the model, the output_dim of the conv section is %d." % output_dim
    activations = []
    dims = [pre_dim]
    if len(L_dim_full_layers):
        for (dim, activation_str, dropout, index) in zip(
                L_dim_full_layers, L_activation_full, L_full_dropout,
                range(len(L_dim_conv_layers),
                      len(L_dim_conv_layers) + len(L_dim_full_layers))):

            # TO DO : leaky relu
            if activation_str.lower() == 'rectifier':
                activation = Rectifier().apply
            elif activation_str.lower() == 'tanh':
                activation = Tanh().apply
            elif activation_str.lower() in ['sigmoid', 'logistic']:
                activation = Logistic().apply
            elif activation_str.lower() in ['id', 'identity']:
                activation = Identity().apply
            else:
                raise Exception("unknown activation function : %s",
                                activation_str)
            activations.append(activation)
            assert 0.0 <= dropout and dropout < 1.0
            dim = dim - int(dim * dropout)
            if allow_comment:
                print "When constructing the fully-connected section, we apply dropout %f to add an MLP going from pre_dim %d to dim %d." % (
                    dropout, pre_dim, dim)
            dims.append(dim)
        #now construct the full MLP in one pass:

    activations.append(Identity())
    #params_channels[index_params]
    dims.append(prediction)
    mlp = MLP(activations=activations,
              dims=dims,
              weights_init=IsotropicGaussian(0.1),
              biases_init=Constant(0.0),
              name="layer_%d" % index)
    mlp.push_allocation_config()
    mlp.initialize()
    return (convnet, mlp)