Getting an AssertionError when using keras - tensorflow

When I run this code, I get the following error and don`t know why?
AssertionError Traceback (most recent call last)
I try again and again, here is my code:
def ConvNet(embeddings, max_sequence_length, num_words, embedding_dim, labels_index, trainable=False, extra_conv=True):
embedding_layer = Embedding(num_words,
embedding_dim,
weights=[embeddings],
input_length=max_sequence_length,
trainable=trainable)
sequence_input = Input(shape=(max_sequence_length,), dtype='int32')
embedded_sequences = embedding_layer(sequence_input)
# Yoon Kim model (https://arxiv.org/abs/1408.5882)
convs = []
filter_sizes = [3,4,5]
for filter_size in filter_sizes:
l_conv = Conv1D(filters=128, kernel_size=filter_size, activation='relu')(embedded_sequences)
l_pool = MaxPooling1D(pool_size=3)(l_conv)
convs.append(l_pool)
l_merge = Concatenate(axis=1)(convs)
# add a 1D convnet with global maxpooling, instead of Yoon Kim model
conv = Conv1D(filters=128, kernel_size=3, activation='relu')(embedded_sequences)
pool = MaxPooling1D(pool_size=3)(conv)
x = (l_merge)
if extra_conv==True:
x = Dropout(0.5)(l_merge)
else:
# Original Yoon Kim model
x = Dropout(0.5)(pool)
x = Flatten()(x)
x = Dense(128, activation='relu')(x)
x = Dropout(0.5)(x)
# Finally, we feed the output into a Sigmoid layer.
# The reason why sigmoid is used is because we are trying to achieve a binary classification(1,0)
# for each of the 6 labels, and the sigmoid function will squash the output between the bounds of 0 and 1.
preds = Dense(labels_index, activation='sigmoid')(x)
model = Model(sequence_input, preds)
model.compile(loss='categorical_crossentropy',
optimizer='adam',
metrics=['acc'])
model.summary()
return model
model = ConvNet(train_embedding_weights, MAX_SEQUENCE_LENGTH, len(train_word_index)+1, EMBEDDING_DIM,
len(list(label_names)), False)
And I get AssertionError.

Related

TypeError: Expected keras.losses.Loss, found function

I want to build a TFF model for speech recognition systems. For this, I use the CNN-GRU model architecture with a CTC loss function. but I got error when I wanted to build_federated_averaging_process and think it's about the ctc_loss function but I cant fix it.
part of my code is:
def CTCLoss(y_true, y_pred):
# Compute the training-time loss value
batch_len = tf.cast(tf.shape(y_true)[0], dtype="int64")
input_length = tf.cast(tf.shape(y_pred)[1], dtype="int64")
label_length = tf.cast(tf.shape(y_true)[1], dtype="int64")
input_length = input_length * tf.ones(shape=(batch_len, 1), dtype="int64")
label_length = label_length * tf.ones(shape=(batch_len, 1), dtype="int64")
loss = keras.backend.ctc_batch_cost(y_true, y_pred, input_length, label_length)
return loss
def create_compiled_keras_model():
"""Model similar to DeepSpeech2."""
# Model's input
input_spectrogram = layers.Input((None, fft_length // 2 + 1), name="input")
# Expand the dimension to use 2D CNN.
x = layers.Reshape((-1, fft_length // 2 + 1 , 1), name="expand_dim")(input_spectrogram)
# Convolution layer 1
x = layers.Conv2D(
filters=32,
kernel_size=[11, 41],
strides=[2, 2],
padding="same",
use_bias=False,
name="conv_1",
)(x)
x = layers.BatchNormalization(name="conv_1_bn")(x)
x = layers.ReLU(name="conv_1_relu")(x)
# Convolution layer 2
x = layers.Conv2D(
filters=32,
kernel_size=[11, 21],
strides=[1, 2],
padding="same",
use_bias=False,
name="conv_2",
)(x)
x = layers.BatchNormalization(name="conv_2_bn")(x)
x = layers.ReLU(name="conv_2_relu")(x)
# Reshape the resulted volume to feed the RNNs layers
x = layers.Reshape((-1, x.shape[-2] * x.shape[-1]))(x)
# RNN layers
for i in range(1, 2 + 1):
recurrent = layers.GRU(
units=128,
activation="tanh",
recurrent_activation="sigmoid",
use_bias=True,
return_sequences=True,
reset_after=True,
name=f"gru_{i}",
)
x = layers.Bidirectional(
recurrent, name=f"bidirectional_{i}", merge_mode="concat"
)(x)
if i < 2:
x = layers.Dropout(rate=0.5)(x)
# Dense layer
x = layers.Dense(units=128 * 2, name="dense_1")(x)
x = layers.ReLU(name="dense_1_relu")(x)
x = layers.Dropout(rate=0.5)(x)
# Classification layer
output = layers.Dense(units= output_dim + 1, activation="softmax")(x)
# Model
model = keras.Model(input_spectrogram, output, name="DeepSpeech_2")
return model
def model_fn():
# We _must_ create a new model here, and _not_ capture it from an external
# scope. TFF will call this within different graph contexts.
keras_model = create_compiled_keras_model()
return tff.learning.from_keras_model(
keras_model,
input_spec=layers.Input((None, fft_length // 2 + 1)),
loss=CTCLoss)
and I got error in this step :
iterative_process = tff.learning.build_federated_averaging_process(
model_fn,
client_optimizer_fn=lambda:keras.optimizers.Adam(learning_rate=1e-4))
TypeError: Expected keras.losses.Loss, found function.
how do I fix it?
class Customloss(tf.keras.losses.Loss):
def __init__(self):
super().__init__()
#tf.function
def CTCLoss(self, y_true, y_pred):
...#
return loss
try to use tf.keras.losses.Loss for custom loss in tff. It will work.

Missing data for input

I want to build a model in TF2 which comprises of the following components: MobilenetV2, 2 layers of BLSTM and then a CTC attached to it. The following demonstrates the model:
def build_model():
img_width = 200
img_height = 50
input_img = layers.Input(shape=(img_width, img_height, 3), name="input_1", dtype="float32")
labels = layers.Input(name="label", shape=(None,), dtype="float32")
base_model=tf.keras.applications.MobileNet(
input_shape=(img_width, img_height, 3),
alpha=1.0,
depth_multiplier=1,
dropout=0.001,
include_top=False,
weights="imagenet",
input_tensor=None,
pooling=None,
classes=1000,
classifier_activation="softmax",
)
x = base_model.output
x = layers.Reshape(target_shape=(6,1024), name="reshape")(x)
x = Bidirectional(layers.LSTM(128, return_sequences=True, dropout=0.25))(x)
x = Bidirectional(layers.LSTM(64, return_sequences=True, dropout=0.25))(x)
output = CTCLayer(name="ctc_loss")(labels, x)
# Define the model
model = keras.models.Model(
inputs=[base_model.input, labels], outputs=output, name="ocr_model_v1"
)
# Optimizer
opt = keras.optimizers.Adam()
# Compile the model and return
model.compile(optimizer=opt)
return model
when I call the build_model function it throws the following error:
ValueError: Missing data for input "input_1". You passed a data dictionary with keys ['image', 'label']. Expected the following keys: ['input_1', 'label']
Any idea how to solve?

What is wrong with my neural networks prediction code? All predictions are returning the same class name for every image

Here is my training code:
def train():
#START
img_input = layers.Input(shape=(150, 150, 3))
x = layers.Conv2D(16, 3, activation='relu')(img_input)
x = layers.MaxPooling2D(2)(x)
x = layers.Conv2D(32, 3, activation='relu')(x)
x = layers.MaxPooling2D(2)(x)
x = layers.Conv2D(64, 3, activation='relu')(x)
x = layers.MaxPooling2D(2)(x)
x = layers.Flatten()(x)
x = layers.Dense(512, activation='relu')(x)
output = layers.Dense(1, activation='sigmoid')(x)
model = Model(img_input, output)
model.compile(loss='binary_crossentropy',
optimizer=RMSprop(lr=0.001),
metrics=['acc'])
#END
# All images will be rescaled by 1./255
train_datagen = ImageDataGenerator(rescale=1./255)
val_datagen = ImageDataGenerator(rescale=1./255)
bs = 20
# Flow training images in batches of 20 using train_datagen generator
train_generator = train_datagen.flow_from_directory(
train_dir, # This is the source directory for training images
target_size=(150, 150), # All images will be resized to 150x150
batch_size=bs,
# Since we use binary_crossentropy loss, we need binary labels
class_mode='binary')
# Flow validation images in batches of 20 using val_datagen generator
validation_generator = val_datagen.flow_from_directory(
validation_dir,
target_size=(150, 150),
batch_size=bs,
class_mode='binary')
history = model.fit(
train_generator,
steps_per_epoch=train_steps,
epochs=4,
validation_data=validation_generator,
validation_steps=val_steps,
verbose=1)
model.save_weights("trained_weights.h5")
Here is my prediction code:
def evaluate(imgpath):
if not os.path.isfile(imgpath):
print("No such file: {}".format(imgpath))
sys.exit(-1)
# START
img_input = layers.Input(shape=(150, 150, 3))
x = layers.Conv2D(16, 3, activation='relu')(img_input)
x = layers.MaxPooling2D(2)(x)
x = layers.Conv2D(32, 3, activation='relu')(x)
x = layers.MaxPooling2D(2)(x)
x = layers.Conv2D(64, 3, activation='relu')(x)
x = layers.MaxPooling2D(2)(x)
x = layers.Flatten()(x)
x = layers.Dense(512, activation='relu')(x)
output = layers.Dense(1, activation='sigmoid')(x)
model = Model(img_input, output)
model.compile(loss='binary_crossentropy',
optimizer=RMSprop(lr=0.001),
metrics=['acc'])
# END
model.load_weights("trained_weights.h5")
img = image.load_img(path=imgpath,grayscale=False,target_size=(150,150),color_mode='rgb')
img_arr = image.img_to_array(img)
test_img = np.expand_dims(img_arr, axis=0)
y_prob = model.predict(test_img)
classname = y_prob.argmax(axis=-1)
print("Class: ",classname)
return classname
I have a feeling that the error is somewhere in the last 5-6 lines of the evaluate function, where I am loading the image. The problem is that whenever I run the evaluate function for any image, my output is [0]. Even though the training went well, as seen in the image below.
enter image description here
Am I making some silly mistake somewhere?
since you have a single neuron as the top layer, when you do predictions you will get a single prediction. Since you have a single prediction using argmax will always return 0. What you need to do is to set a threshold value for the prediction for example
if yprob>=.5:
klass=1
else:
klass=0
Also as pointed out by Dr. Snoopy you should rescale your image by 1/255.

DeblurGAN can't load his own weights anymore

Hey I realy need some help =)
firstly, sorry that it's soo long^^ but I hope that you don't need the full code at the end.
I coded a GAN for deblurring. Now I'm training it. the first 71 epochs have been trained without any problems: I trained some epochs till the colab GPU-time limit was reached, the next day I loaded my weights into the gan and continued training.
2 or 3 weeks ago I wanted to load the weights of epoch 71 in my Gan but I recieved the following error (I'm quite sure that I didn't change anything in the code). Since this moment I only can load the first 65 weights and i get the same error for every epoch higher than 65:
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-16-a35c9a2bbf3a> in <module>()
1 # Load weights
----> 2 gan.load_weights(F"/content/gdrive/My Drive/Colab Notebooks/data/deblurGAN_weights66_batchsize_1.h5")
5 frames
/usr/local/lib/python3.6/dist-packages/tensorflow/python/keras/engine/training.py in load_weights(self, filepath, by_name, skip_mismatch, options)
2209 f, self.layers, skip_mismatch=skip_mismatch)
2210 else:
-> 2211 hdf5_format.load_weights_from_hdf5_group(f, self.layers)
2212
2213 def _updated_config(self):
/usr/local/lib/python3.6/dist-packages/tensorflow/python/keras/saving/hdf5_format.py in load_weights_from_hdf5_group(f, layers)
706 str(len(weight_values)) + ' elements.')
707 weight_value_tuples += zip(symbolic_weights, weight_values)
--> 708 K.batch_set_value(weight_value_tuples)
709
710
/usr/local/lib/python3.6/dist-packages/tensorflow/python/util/dispatch.py in wrapper(*args, **kwargs)
199 """Call target, and fall back on dispatchers if there is a TypeError."""
200 try:
--> 201 return target(*args, **kwargs)
202 except (TypeError, ValueError):
203 # Note: convert_to_eager_tensor currently raises a ValueError, not a
/usr/local/lib/python3.6/dist-packages/tensorflow/python/keras/backend.py in batch_set_value(tuples)
3574 if ops.executing_eagerly_outside_functions():
3575 for x, value in tuples:
-> 3576 x.assign(np.asarray(value, dtype=dtype(x)))
3577 else:
3578 with get_graph().as_default():
/usr/local/lib/python3.6/dist-packages/tensorflow/python/ops/resource_variable_ops.py in assign(self, value, use_locking, name, read_value)
856 with _handle_graph(self.handle):
857 value_tensor = ops.convert_to_tensor(value, dtype=self.dtype)
--> 858 self._shape.assert_is_compatible_with(value_tensor.shape)
859 assign_op = gen_resource_variable_ops.assign_variable_op(
860 self.handle, value_tensor, name=name)
/usr/local/lib/python3.6/dist-packages/tensorflow/python/framework/tensor_shape.py in assert_is_compatible_with(self, other)
1132 """
1133 if not self.is_compatible_with(other):
-> 1134 raise ValueError("Shapes %s and %s are incompatible" % (self, other))
1135
1136 def most_specific_compatible_shape(self, other):
ValueError: Shapes (4, 4, 64, 128) and (64,) are incompatible
I was looking a long time for a solution and i didn't find a real one. But I found out, that if I train one epoch with one of the old weights (1-65) afterwards I can load one of the new weights. So I thought that I could use this "workaround" but yesterday I plotted the scores of the metric of the Test dataset for every epoch. I recieved this picture:
psnrscore/epoch
as you can see it looks like I'm producing trash since epoch 65 (on the pic since 60 because I lost the first 5 epochs, so it starts by 6)
I'm realy frustrated and hope that someone could help me =D
Here's the full code of the GAN:
# Libraries to build the model
from tensorflow import pad
from tensorflow.keras.layers import Layer
from keras.layers import Input, Activation, Add, UpSampling2D
from keras.layers.merge import Add
from keras.layers.core import Dropout, Dense, Flatten
from keras.layers.advanced_activations import LeakyReLU
from keras.layers.convolutional import Conv2D, Conv2DTranspose
from keras.layers.core import Lambda
from keras.layers.normalization import BatchNormalization
from keras.models import Model
import keras.backend as K
from keras.applications.vgg16 import VGG16
from keras.optimizers import Adam
import keras
# Reflection padding
from keras.engine import InputSpec
import tensorflow as tf
from keras.engine.topology import Layer
'''
2D Reflection Padding
Attributes:
- padding: (padding_width, padding_height) tuple
'''
class ReflectionPadding2D(Layer):
def __init__(self, padding=(1, 1), **kwargs):
self.padding = tuple(padding)
self.input_spec = [InputSpec(ndim=4)]
super(ReflectionPadding2D, self).__init__(**kwargs)
def compute_output_shape(self, s):
""" If you are using "channels_last" configuration"""
return (s[0], s[1] + 2 * self.padding[0], s[2] + 2 * self.padding[1], s[3])
def call(self, x, mask=None):
w_pad,h_pad = self.padding
return tf.pad(x, [[0,0], [h_pad,h_pad], [w_pad,w_pad], [0,0] ], 'REFLECT')
# Res Block
def res_block(input, filters, kernel_size = (3,3), strides = (1,1), use_dropout = False):
"""
Instanciate a Keras Resnet Block using sequential API.
:param input: Input tensor
:param filters: Number of filters to use
:param kernel_size: Shape of the kernel for the convolution
:param strides: Shape of the strides for the convolution
:param use_dropout: Boolean value to determine the use of dropout
:return: Keras Model
"""
x = ReflectionPadding2D((1,1))(input)
x = Conv2D(filters = filters,
kernel_size = kernel_size,
strides = strides,)(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
if use_dropout:
x = Dropout(0.5)(x)
x = ReflectionPadding2D((1,1))(x)
x = Conv2D(filters = filters,
kernel_size = kernel_size,
strides = strides,)(x)
x = BatchNormalization()(x)
# Two convolution layers followed by a direct connection between input and output (skip connection)
out = Add()([input, x])
return out
# Generator
n_res_blocks = 9
def generator_model():
# encoder
inputs = Input(shape = img_shape)
x = ReflectionPadding2D((3, 3))(inputs)
x = Conv2D(filters = 64, kernel_size = (7,7), padding = 'valid')(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
x = Conv2D(128, (3,3), strides=2, padding='same') (x) #DIM(15,15,128)
x = BatchNormalization() (x)
x = Activation('relu') (x)
x = Conv2D(256, (3,3), strides = 2, padding = 'same') (x) #DIM(7,7,256)
x = BatchNormalization() (x)
x = Activation('relu') (x)
# Apply 9 res blocks
for i in range(n_res_blocks):
x = res_block(x, 256, use_dropout = True)
# decoder
#x = Conv2DTranspose(128, (3,3), strides = 2, padding = 'same') (x)
x = UpSampling2D()(x)
x = Conv2D(filters = 128, kernel_size=(3, 3), padding='same')(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
#x = Conv2DTranspose(64, (3,3), strides = 2, padding = 'same') (x)
x = UpSampling2D()(x)
x = Conv2D(filters = 64, kernel_size=(3, 3), padding='same')(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
x = ReflectionPadding2D((3,3))(x)
x = Conv2D(filters = 3, kernel_size = (7,7), padding = 'valid')(x)
x = Activation('tanh')(x)
# Add direct connection from input to output and recenter to [-1, 1] (skip connection)
outputs = Add()([x, inputs])
outputs = Lambda(lambda z: z/2)(outputs) # to keep normalized outputs
model = Model(inputs = inputs, outputs = outputs, name = 'Generator')
return model
# Discriminator
def discriminator_model():
Input_img = Input(shape=(img_shape))
x = Conv2D(filters = 64, kernel_size = (4, 4), strides = 2, padding='same')(Input_img)
x = LeakyReLU(0.2)(x)
nf_mult, nf_mult_prev = 1, 1
for n in range(3):
nf_mult_prev, nf_mult = nf_mult, min(2**n, 8)
x = Conv2D(filters = 64*nf_mult, kernel_size = (4, 4), strides = 2, padding = 'same')(x)
x = BatchNormalization()(x)
x = LeakyReLU(0.2)(x)
nf_mult_prev, nf_mult = nf_mult, 8
x = Conv2D(filters = 64*nf_mult, kernel_size = (4, 4), strides = 1, padding = 'same')(x)
x = BatchNormalization()(x)
x = LeakyReLU(0.2)(x)
x = Conv2D(filters = 1, kernel_size = (4, 4), strides = 1, padding = 'same')(x)
x = Flatten()(x)
x = Dense(1024, activation = 'tanh')(x)
x = Dense(1, activation = 'sigmoid')(x)
model = Model(inputs = Input_img, outputs = x, name = 'discriminator')
return model
def gan_model(generator, discriminator):
inputs = Input(shape = img_shape)
generated_images = generator(inputs)
outputs = discriminator(generated_images)
model = Model(inputs=inputs, outputs = [generated_images, outputs])
return model
#Losses
#Wassersteinloss:
def wasserstein_loss(y_true, y_pred):
return K.mean(y_true * y_pred)
# vgg16 model for perceptual loss
vgg = VGG16(include_top = False, weights = 'imagenet', input_shape = img_shape)
loss_model = Model(inputs = vgg.input, outputs = vgg.get_layer('block3_conv3').output)
loss_model.trainable = False
#perceptual loss:
def perceptual_loss(y_true, y_pred):
return K.mean(K.square(loss_model(y_true) - loss_model(y_pred)))
#Metrics:
#SSIM:
def ssim_metric(y_true, y_pred):
return tf.reduce_mean(tf.image.ssim(tf.convert_to_tensor(y_true),tf.convert_to_tensor(y_pred), max_val=1.0, ))
#PSNR:
def psnr_metric(y_true, y_pred):
return tf.reduce_mean(tf.image.psnr(y_true, y_pred, max_val=1.0))
def training(epochs, batch_size):
path_psnr = F"/content/gdrive/My Drive/Colab Notebooks/data/psnr"
path_ssim = F"/content/gdrive/My Drive/Colab Notebooks/data/ssim"
GAN_losses = []
#psnrs = []
#ssims = []
random_idx = np.arange(0, X_train.shape[0])
n_batches = int (len(random_idx)/batch_size) #divide trainingset into batches of batch_size
for e in range(epochs):
#weights_name = "deblurGAN_weights%s_batchsize_%r.h5" %(e + 66, batch_size)
weights_name = "deblurGAN_weights_test.h5"
print("epoch: %s " %(e + 66))
#randomize index of trainig set
random.shuffle(random_idx)
for i in range(n_batches):
img_batch_blured = X_train[i*batch_size:(i+1)*batch_size]
img_batch_generated = generator.predict(img_batch_blured)
img_batch_original = Y_train[i*batch_size:(i+1)*batch_size]
img_batch = np.concatenate((img_batch_generated , img_batch_original),0)
valid0 = -np.ones(batch_size)
valid1 = np.ones(batch_size)
valid = np.concatenate((valid0,valid1))
discriminator.trainable = True
for k in range(5):
loss = discriminator.train_on_batch(img_batch, valid)
discriminator.trainable = False
GAN_loss = gan.train_on_batch(img_batch_blured, [img_batch_original, valid1])
GAN_losses.append(GAN_loss)
if (100*i/n_batches).is_integer():
psnr = psnr_metric(img_batch_original, img_batch_generated)
ssim = ssim_metric(img_batch_original, img_batch_generated)
psnrs.append(psnr)
ssims.append(ssim)
#creating 2 files in Google Drive where the psnr and ssim data will be saved.
pickle.dump( psnrs, open( path_psnr, "wb" ) )
pickle.dump( ssims, open( path_ssim, "wb" ) )
print((100*i/n_batches) + 1, "% psnr: ", psnr," ssim: ", ssim)
# Save weights: mode the path to your directory
gan.save_weights(F"/content/gdrive/My Drive/Colab Notebooks/data/{weights_name}")
return [GAN_losses, psnrs, ssims]
# Initialize models
generator = generator_model()
discriminator = discriminator_model()
gan = gan_model(generator, discriminator)
# Initialize optimizers
d_opt = Adam(lr=1E-4, beta_1=0.9, beta_2=0.999, epsilon=1e-08)
gan_opt = Adam(lr=1E-4, beta_1=0.9, beta_2=0.999, epsilon=1e-08)
# Compile models
discriminator.trainable = True
discriminator.compile(optimizer = d_opt, loss = wasserstein_loss)
discriminator.trainable = False
loss = [perceptual_loss, wasserstein_loss]
loss_weights = [100, 1]
gan.compile(optimizer = gan_opt, loss = loss, loss_weights = loss_weights)
discriminator.trainable = True
gan.summary()
# Load weights
gan.load_weights(F"/content/gdrive/My Drive/Colab Notebooks/data/deblurGAN_weights66_batchsize_1.h5")
#connect to GPU
device_name = tf.test.gpu_device_name()
if device_name != '/device:GPU:0':
raise SystemError('GPU device not found')
print('Found GPU at: {}'.format(device_name))
loss = training(1, 1) #epochs, batchsize
It is solved an can be closed. I didn't know that the "discriminato.Trainable = True/False" was changed. It seems to be the reason for another ordering in the weights.

Average weights in keras models

How to average weights in Keras models, when I train few models with the same architecture with different initialisations?
Now my code looks something like this?
datagen = ImageDataGenerator(rotation_range=15,
width_shift_range=2.0/28,
height_shift_range=2.0/28
)
epochs = 40
lr = (1.234e-3)
optimizer = Adam(lr=lr)
main_input = Input(shape= (28,28,1), name='main_input')
sub_models = []
for i in range(5):
x = Conv2D(32, kernel_size=(3,3), strides=1)(main_input)
x = BatchNormalization()(x)
x = Activation('relu')(x)
x = MaxPool2D(pool_size=2)(x)
x = Conv2D(64, kernel_size=(3,3), strides=1)(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
x = MaxPool2D(pool_size=2)(x)
x = Conv2D(64, kernel_size=(3,3), strides=1)(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
x = Flatten()(x)
x = Dense(1024)(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
x = Dropout(0.1)(x)
x = Dense(256)(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
x = Dropout(0.4)(x)
x = Dense(10, activation='softmax')(x)
sub_models.append(x)
x = keras.layers.average(sub_models)
main_output = keras.layers.average(sub_models)
model = Model(inputs=[main_input], outputs=[main_output])
model.compile(loss='categorical_crossentropy', metrics=['accuracy'],
optimizer=optimizer)
print(model.summary())
plot_model(model, to_file='model.png')
filepath="weights.best.hdf5"
checkpoint = ModelCheckpoint(filepath, monitor='val_acc', verbose=1, save_best_only=True, mode='max')
tensorboard = TensorBoard(log_dir='./Graph', histogram_freq=0, write_graph=True, write_images=True)
callbacks = [checkpoint, tensorboard]
model.fit_generator(datagen.flow(X_train, y_train, batch_size=128),
steps_per_epoch=len(X_train) / 128,
epochs=epochs,
callbacks=callbacks,
verbose=1,
validation_data=(X_test, y_test))
So now I average only last layer, but I want to average weights in all layers after training each one separately.
Thanks!
So let's assume that models is a collection of your models. First - collect all weights:
weights = [model.get_weights() for model in models]
Now - create a new averaged weights:
new_weights = list()
for weights_list_tuple in zip(*weights):
new_weights.append(
[numpy.array(weights_).mean(axis=0)\
for weights_ in zip(*weights_list_tuple)])
And what is left is to set these weights in a new model:
new_model.set_weights(new_weights)
Of course - averaging weights might be a bad idea, but in case you try - you should follow this approach.
I can't comment on the accepted answer, but to make it work on tensorflow 2.0 with tf.keras I had to make the list in the loop into a numpy array:
new_weights = list()
for weights_list_tuple in zip(*weights):
new_weights.append(
np.array([np.array(w).mean(axis=0) for w in zip(*weights_list_tuple)])
)
If different input models need to be weighted differently, np.array(w).mean(axis=0) needs to be replaced with np.average(np.array(w),axis=0, weights=relative_weights) where relative_weights is an array with a weight factor for each model.