Python layers.Lambda方法代码示例

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def crop(dimension, start, end):
    # Crops (or slices) a Tensor on a given dimension from start to end
    # example : to crop tensor x[:, :, 5:10]
    # call slice(2, 5, 10) as you want to crop on the second dimension
    def func(x):
        if dimension == 0:
            return x[start: end]
        if dimension == 1:
            return x[:, start: end]
        if dimension == 2:
            return x[:, :, start: end]
        if dimension == 3:
            return x[:, :, :, start: end]
        if dimension == 4:
            return x[:, :, :, :, start: end]
    return Lambda(func) 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def get_model_41(params):
    embedding_weights = pickle.load(open("../data/datasets/train_data/embedding_weights_w2v-google_MSD-AG.pk","rb"))
    # main sequential model
    model = Sequential()
    model.add(Embedding(len(embedding_weights[0]), params['embedding_dim'], input_length=params['sequence_length'],
                        weights=embedding_weights))
    #model.add(Dropout(params['dropout_prob'][0], input_shape=(params['sequence_length'], params['embedding_dim'])))
    model.add(LSTM(2048))
    #model.add(Dropout(params['dropout_prob'][1]))
    model.add(Dense(output_dim=params["n_out"], init="uniform"))
    model.add(Activation(params['final_activation']))
    logging.debug("Output CNN: %s" % str(model.output_shape))

    if params['final_activation'] == 'linear':
        model.add(Lambda(lambda x :K.l2_normalize(x, axis=1)))

    return model


# CRNN Arch for audio 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def yolo_body(inputs, num_anchors, num_classes):
    """Create YOLO_V2 model CNN body in Keras."""
    darknet = Model(inputs, darknet_body()(inputs))
    conv13 = darknet.get_layer('batchnormalization_13').output
    conv20 = compose(
        DarknetConv2D_BN_Leaky(1024, 3, 3),
        DarknetConv2D_BN_Leaky(1024, 3, 3))(darknet.output)

    # TODO: Allow Keras Lambda to use func arguments for output_shape?
    conv13_reshaped = Lambda(
        space_to_depth_x2,
        output_shape=space_to_depth_x2_output_shape,
        name='space_to_depth')(conv13)

    # Concat conv13 with conv20.
    x = merge([conv13_reshaped, conv20], mode='concat')
    x = DarknetConv2D_BN_Leaky(1024, 3, 3)(x)
    x = DarknetConv2D(num_anchors * (num_classes + 5), 1, 1)(x)
    return Model(inputs, x) 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def yolo_body(inputs, num_anchors, num_classes):
    """Create YOLO_V2 model CNN body in Keras."""
    darknet = Model(inputs, darknet_body()(inputs))
    conv20 = compose(
        DarknetConv2D_BN_Leaky(1024, (3, 3)),
        DarknetConv2D_BN_Leaky(1024, (3, 3)))(darknet.output)

    conv13 = darknet.layers[43].output
    conv21 = DarknetConv2D_BN_Leaky(64, (1, 1))(conv13)
    # TODO: Allow Keras Lambda to use func arguments for output_shape?
    conv21_reshaped = Lambda(
        space_to_depth_x2,
        output_shape=space_to_depth_x2_output_shape,
        name='space_to_depth')(conv21)

    x = concatenate([conv21_reshaped, conv20])
    x = DarknetConv2D_BN_Leaky(1024, (3, 3))(x)
    x = DarknetConv2D(num_anchors * (num_classes + 5), (1, 1))(x)
    return Model(inputs, x) 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def GenerateMCSamples(inp, layers, K_mc=20):
    if K_mc == 1:
        return apply_layers(inp, layers)
    output_list = []
    for _ in xrange(K_mc):
        output_list += [apply_layers(inp, layers)]  # THIS IS BAD!!! we create new dense layers at every call!!!!
    def pack_out(output_list):
        #output = K.pack(output_list) # K_mc x nb_batch x nb_classes
        output = K.stack(output_list) # K_mc x nb_batch x nb_classes
        return K.permute_dimensions(output, (1, 0, 2)) # nb_batch x K_mc x nb_classes
    def pack_shape(s):
        s = s[0]
        assert len(s) == 2
        return (s[0], K_mc, s[1])
    out = Lambda(pack_out, output_shape=pack_shape)(output_list)
    return out

# evaluation for classification tasks 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def SiameseNetwork(input_shape=(5880,)):
    base_network = create_base_network(input_shape)

    input_a = Input(shape=input_shape)
    input_b = Input(shape=input_shape)

    processed_a = base_network(input_a)
    processed_b = base_network(input_b)

    distance = Lambda(euclidean_distance,
                  output_shape=eucl_dist_output_shape)([processed_a, processed_b])

    model = Model([input_a, input_b], distance)

    rms = RMSprop()
    model.compile(loss=contrastive_loss, optimizer=rms, metrics=[accuracy])
    
    return model, base_network 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def Highway(x, num_layers=1, activation='relu', name_prefix=''):
    '''
    Layer wrapper function for Highway network
    # Arguments:
        x: tensor, shape = (B, input_size)
    # Optional Arguments:
        num_layers: int, dafault is 1, the number of Highway network layers
        activation: keras activation, default is 'relu'
        name_prefix: str, default is '', layer name prefix
    # Returns:
        out: tensor, shape = (B, input_size)
    '''
    input_size = K.int_shape(x)[1]
    for i in range(num_layers):
        gate_ratio_name = '{}Highway/Gate_ratio_{}'.format(name_prefix, i)
        fc_name = '{}Highway/FC_{}'.format(name_prefix, i)
        gate_name = '{}Highway/Gate_{}'.format(name_prefix, i)

        gate_ratio = Dense(input_size, activation='sigmoid', name=gate_ratio_name)(x)
        fc = Dense(input_size, activation=activation, name=fc_name)(x)
        x = Lambda(lambda args: args[0] * args[2] + args[1] * (1 - args[2]), name=gate_name)([fc, x, gate_ratio])
    return x 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def model_masking(discrete_time, init_alpha, max_beta):
    model = Sequential()

    model.add(Masking(mask_value=mask_value,
                      input_shape=(n_timesteps, n_features)))
    model.add(TimeDistributed(Dense(2)))
    model.add(Lambda(wtte.output_lambda, arguments={"init_alpha": init_alpha,
                                                    "max_beta_value": max_beta}))

    if discrete_time:
        loss = wtte.loss(kind='discrete', reduce_loss=False).loss_function
    else:
        loss = wtte.loss(kind='continuous', reduce_loss=False).loss_function

    model.compile(loss=loss, optimizer=RMSprop(
        lr=lr), sample_weight_mode='temporal')
    return model 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def train(model, image_data, y_true, log_dir='logs/'):
    '''retrain/fine-tune the model'''
    model.compile(optimizer='adam', loss={
        # use custom yolo_loss Lambda layer.
        'yolo_loss': lambda y_true, y_pred: y_pred})

    logging = TensorBoard(log_dir=log_dir)
    checkpoint = ModelCheckpoint(log_dir + "ep{epoch:03d}-loss{loss:.3f}-val_loss{val_loss:.3f}.h5",
        monitor='val_loss', save_weights_only=True, save_best_only=True)
    early_stopping = EarlyStopping(monitor='val_loss', min_delta=0, patience=5, verbose=1, mode='auto')

    model.fit([image_data, *y_true],
              np.zeros(len(image_data)),
              validation_split=.1,
              batch_size=32,
              epochs=30,
              callbacks=[logging, checkpoint, early_stopping])
    model.save_weights(log_dir + 'trained_weights.h5')
    # Further training. 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def channel_shuffle_lambda(channels,
                           groups,
                           **kwargs):
    """
    Channel shuffle layer. This is a wrapper over the same operation. It is designed to save the number of groups.

    Parameters:
    ----------
    channels : int
        Number of channels.
    groups : int
        Number of groups.

    Returns
    -------
    Layer
        Channel shuffle layer.
    """
    assert (channels % groups == 0)

    return nn.Lambda(channel_shuffle, arguments={"groups": groups}, **kwargs) 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def get_variational_encoder(node_num, d,
                            n_units, nu1, nu2,
                            activation_fn):
    K = len(n_units) + 1
    # Input
    x = Input(shape=(node_num,))
    # Encoder layers
    y = [None] * (K + 3)
    y[0] = x
    for i in range(K - 1):
        y[i + 1] = Dense(n_units[i], activation=activation_fn,
                         W_regularizer=Reg.l1_l2(l1=nu1, l2=nu2))(y[i])
    y[K] = Dense(d, activation=activation_fn,
                 W_regularizer=Reg.l1_l2(l1=nu1, l2=nu2))(y[K - 1])
    y[K + 1] = Dense(d)(y[K - 1])
    # y[K + 1] = Dense(d, W_regularizer=Reg.l1_l2(l1=nu1, l2=nu2))(y[K - 1])
    y[K + 2] = Lambda(sampling, output_shape=(d,))([y[K], y[K + 1]])
    # Encoder model
    encoder = Model(input=x, outputs=[y[K], y[K + 1], y[K + 2]])
    return encoder 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def profile_contrib(p):
    return kl.Lambda(lambda p:
                     K.mean(K.sum(K.stop_gradient(tf.nn.softmax(p, dim=-2)) * p, axis=-2), axis=-1)
                     )(p) 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def channel_split(self, x):
        def splitter(y):
            # keras Lambda saving bug!!!
            # x_left = layers.Lambda(lambda y: y[:, :, :, :int(int(y.shape[-1]) // self.groups)])(x)
            # x_right = layers.Lambda(lambda y: y[:, :, :, int(int(y.shape[-1]) // self.groups):])(x)
            # return x_left, x_right
            return tf.split(y, num_or_size_splits=self.groups, axis=-1)

        return layers.Lambda(lambda y: splitter(y))(x) 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def get_model_3(params):

    # metadata
    inputs2 = Input(shape=(params["n_metafeatures"],))
    x2 = Dropout(params["dropout_factor"])(inputs2)

    if params["n_dense"] > 0:
        dense2 = Dense(output_dim=params["n_dense"], init="uniform", activation='relu')
        x2 = dense2(x2)
        logging.debug("Output CNN: %s" % str(dense2.output_shape))

        x2 = Dropout(params["dropout_factor"])(x2)

    if params["n_dense_2"] > 0:
        dense3 = Dense(output_dim=params["n_dense_2"], init="uniform", activation='relu')
        x2 = dense3(x2)
        logging.debug("Output CNN: %s" % str(dense3.output_shape))

        x2 = Dropout(params["dropout_factor"])(x2)

    dense4 = Dense(output_dim=params["n_out"], init="uniform", activation=params['final_activation'])
    xout = dense4(x2)
    logging.debug("Output CNN: %s" % str(dense4.output_shape))

    if params['final_activation'] == 'linear':
        reg = Lambda(lambda x :K.l2_normalize(x, axis=1))
        xout = reg(xout)

    model = Model(input=inputs2, output=xout)

    return model


# Metadata 2 inputs, post-merge with dense layers 

# 需要导入模块: from keras import layers [as 别名]
# 或者: from keras.layers import Lambda [as 别名]
def get_model_32(params):

    # metadata
    inputs = Input(shape=(params["n_metafeatures"],))
    reg = Lambda(lambda x :K.l2_normalize(x, axis=1))
    x1 = reg(inputs)

    inputs2 = Input(shape=(params["n_metafeatures2"],))
    reg2 = Lambda(lambda x :K.l2_normalize(x, axis=1))
    x2 = reg2(inputs2)

    # merge
    x = merge([x1, x2], mode='concat', concat_axis=1)

    x = Dropout(params["dropout_factor"])(x)

    if params['n_dense'] > 0:
        dense2 = Dense(output_dim=params["n_dense"], init="uniform", activation='relu')
        x = dense2(x)
        logging.debug("Output CNN: %s" % str(dense2.output_shape))

    dense4 = Dense(output_dim=params["n_out"], init="uniform", activation=params['final_activation'])
    xout = dense4(x)
    logging.debug("Output CNN: %s" % str(dense4.output_shape))

    if params['final_activation'] == 'linear':
        reg = Lambda(lambda x :K.l2_normalize(x, axis=1))
        xout = reg(xout)

    model = Model(input=[inputs,inputs2], output=xout)

    return model

# Metadata 3 inputs, pre-merge and l2