During training the TensorFlow model(!!Not the Keras model), How to get the input and output of the intermediate layer(op) of the model?

Question:

During training the TensorFlow model(!!Not the Keras model), is possible to get the input and output of the intermediate layer(op) of the model?

I use the example from Tensorflow tutorial as the demo:

To explain more clearly, I made a few changes to the model without changing its purpose.

Tensorflow Version: 2.8.0

class MyModel(Model):
  def __init__(self):
    super(MyModel, self).__init__()
    self.conv1 = Conv2D(32, 3, activation='relu')
    self.flatten = Flatten()
    self.d1 = Dense(128, activation='relu')
    self.d2 = Dense(10)

  def call(self, x):
    # x = self.conv1(x)
    # x = self.flatten(x)
    # x = self.d1(x)
    # return self.d2(x)
    x1 = self.conv1(x) 
    x2 = self.flatten(x1)
    x3 = self.d1(x2)
    return self.d2(x3)

Is possible to get the x1, x2, and x3 in the model or the input and output of self.conv1?

Asked By: Ausrada404

||

Answers:

I would recommend using a custom Keras callback to feed data to the model during training and then saving the weights and outputs. You can feed the callback your training data or other data, for example your test data:

import tensorflow as tf
import numpy as np

class MyModel(tf.keras.Model):
  def __init__(self):
    super(MyModel, self).__init__()
    self.conv1 = tf.keras.layers.Conv2D(32, 3, activation='relu')
    self.flatten = tf.keras.layers.Flatten()
    self.d1 = tf.keras.layers.Dense(128, activation='relu')
    self.d2 = tf.keras.layers.Dense(10)

  def call(self, x):
    x1 = self.conv1(x) 
    x2 = self.flatten(x1)
    x3 = self.d1(x2)
    return self.d2(x3)

class CustomCallback(tf.keras.callbacks.Callback):
   def __init__(self, data):
        self.data = data
   def on_epoch_end(self, epoch, logs=None):
        #if epoch == some_value: <-- can also define a condition
        conv_layer = self.model.layers[0]
        outputs = conv_layer(self.data)
        np.save('conv_outputs', np.array(outputs)) 
        np.save('conv_weights', np.array(conv_layer.weights))
        tf.print('Saved Conv2D outputs and weights')

model = MyModel()
x_train = tf.random.normal((10, 32, 32, 3))
x_test = tf.random.normal((10, 32, 32, 3))
model.compile(optimizer='adam', loss = tf.keras.losses.SparseCategoricalCrossentropy(True))
model.fit(x_train, tf.random.uniform((10, 1), maxval=10), epochs=2, callbacks=[CustomCallback(x_test)], batch_size=2)
Answered By: AloneTogether

There are many ways but I think about the purpose when model learning you can assigned some values to the model as you start with the custom class and in the same way you can read the layer weight or output from model( X ) or model.predict( X ) value.

[ Sample ] :

import os
from os.path import exists

import gym
import ale_py

import tensorflow as tf
import tensorflow_io as tfio

import matplotlib.pyplot as plt
import matplotlib.animation as animation

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
[PhysicalDevice(name='/physical_device:GPU:0', device_type='GPU')]
None
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
physical_devices = tf.config.experimental.list_physical_devices('GPU')
assert len(physical_devices) > 0, "Not enough GPU hardware devices available"
config = tf.config.experimental.set_memory_growth(physical_devices[0], True)
print(physical_devices)
print(config)

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
: Games Environments
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
env = gym.make("ALE/ChopperCommand-v5")
n_outputs = env.action_space.n
obs = env.reset()
observation, reward, done, info = env.step(1)

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
: Variables
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
global step
global action
step = 1
action = 1
CROP_SIZE = [ 210, 160 ]
IMAGE_SIZE = [ 210, 160, 3 ] 
BATCH_SIZE = 1
NUM_BOXES = 1
LONG_STEPS = 100000000000

boxes = tf.constant([ 0.26, 0.05, 0.8, 1.0 ], shape=(1, 4))
box_indices = tf.constant([ 0 ], shape=(1, ))

fig = plt.figure()
image = plt.imread( "F:\datasets\downloads\cats_name\train\Symbols\01.jpg" )
im = plt.imshow(image)

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
: Class / Definition
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
class MyModel(tf.keras.Model):
    def __init__(self):
        super().__init__()
        self.optimizer = tf.keras.optimizers.Nadam( learning_rate=0.00001, beta_1=0.9, beta_2=0.999, epsilon=1e-07, name='Nadam')
        self.lossfn = tf.keras.losses.SparseCategoricalCrossentropy( from_logits=False, reduction=tf.keras.losses.Reduction.AUTO, name='sparse_categorical_crossentropy' )
        
        self.input1 = tf.keras.layers.InputLayer(input_shape=( 210, 160, 1 ), name="input_01")
        self.normalize1 = tf.keras.layers.Normalization(mean=3., variance=2., name="normalize_01"),
        self.normalize2 = tf.keras.layers.Normalization(mean=4., variance=6., name="normalize_01"),
        self.conv2d = tf.keras.layers.Conv2D(32, (3, 3), activation='relu')
        self.maxpool2d = tf.keras.layers.MaxPooling2D((2, 2))
        self.dense1 = tf.keras.layers.Dense(4, activation=tf.nn.relu, name="Dense_01")
        self.dense2 = tf.keras.layers.Dense(5, activation=tf.nn.softmax, name="Dense_02")
        self.dense3 = tf.keras.layers.Dense(16, activation=tf.nn.softmax, name="Dense_03")
        self.flattern = tf.keras.layers.Flatten(name="flattern")
        self.model = tf.keras.models.Sequential([
            self.input1,
            tf.keras.layers.Normalization(mean=3., variance=2.),
            tf.keras.layers.Normalization(mean=4., variance=6.),
            tf.keras.layers.Conv2D(32, (3, 3), activation='relu'),
            tf.keras.layers.MaxPooling2D((2, 2)),
            tf.keras.layers.Flatten(name="flattern"),
            self.dense3,
        ])
    
    def call(self, inputs, training=None):
        result = self.model( inputs, training  )
        
        return result

def animate( i ):
    global step
    global action

    step = step + 1
    
    observation, reward, done, info = env.step(action)
    env.render()
    im.set_array( observation )
    
    image_array = tf.keras.preprocessing.image.img_to_array( observation )
    image_cropped = tf.image.crop_and_resize( tf.expand_dims(image_array, axis=0), boxes, box_indices, CROP_SIZE )
    image_cropped = tf.reshape( image_cropped[0], IMAGE_SIZE )
    # grey scales
    image_greyscales = tf.image.rgb_to_grayscale( image_cropped ).numpy()
    
    prediction_result = model.predict(tf.constant(tf.cast(image_greyscales, dtype=tf.int64), shape=(1, 210, 160, 1), dtype=tf.int64))
    action = tf.constant(tf.math.argmax( prediction_result[0] ), shape=(1, 1, 1), dtype=tf.int64)[0][0][0].numpy()
    
    if reward > 0 :
        input_dataset = tf.constant(tf.cast(image_greyscales, dtype=tf.int64 ), shape=(1, 1, 210, 160, 1), dtype=tf.int64)
        label_dataset = tf.constant( action, shape=(1, 1, 1), dtype=tf.int64 )
        dataset = tf.data.Dataset.from_tensor_slices(( input_dataset, label_dataset ))
        history = model.fit( dataset, batch_size=100, epochs=10, callbacks=[custom_callback] )
    else :

        if step % 8 == 0 :
            action = random_action( action )
            observation, reward, done, info = env.step(action)
            env.render()
            im.set_array( observation )
            
            image_array = tf.keras.preprocessing.image.img_to_array( observation )
            image_cropped = tf.image.crop_and_resize( tf.expand_dims(image_array, axis=0), boxes, box_indices, CROP_SIZE )
            image_cropped = tf.reshape( image_cropped[0], IMAGE_SIZE )
            image_greyscales = tf.image.rgb_to_grayscale( image_cropped ).numpy()
            
            input_dataset = tf.constant(tf.cast(image_greyscales, dtype=tf.int64 ), shape=(1, 1, 210, 160, 1), dtype=tf.int64)
            label_dataset = tf.constant( action, shape=(1, 1, 1), dtype=tf.int64 )
            dataset = tf.data.Dataset.from_tensor_slices(( input_dataset, label_dataset ))
            history = model.fit( dataset, batch_size=100, epochs=10, callbacks=[custom_callback] )
        else :
            pass

    plt.xlabel( str(step) + ": action = " + str( action ) )
    plt.show()
    return im,
    
def random_action(action): 

    temp = tf.random.normal([n_outputs], 1, 0.2, tf.float32)
    # temp_2 = tf.constant( tf.ones(( n_outputs )) * 48 )
    action = tf.math.argmax(temp).numpy()

    return action

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
: Callback
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
class custom_callback(tf.keras.callbacks.Callback):
    def on_epoch_end(self, epoch, logs={}):
        if( logs['accuracy'] >= 0.97 ):
            self.model.stop_training = True
            return
        else :
            output_layer = self.model.get_layer( name="Dense_03" )  #   <keras.layers.core.dense.Dense object at 0x000002CB9D3267F0>
            # you may utilize the model training weight here
    
custom_callback = custom_callback()
    
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
: DataSet
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
image_array = tf.keras.preprocessing.image.img_to_array( observation )
image_cropped = tf.image.crop_and_resize( tf.expand_dims(image_array, axis=0), boxes, box_indices, CROP_SIZE )
image_cropped = tf.reshape( image_cropped[0], IMAGE_SIZE )
# grey scales
image_greyscales = tf.image.rgb_to_grayscale( image_cropped ).numpy()

input_dataset = tf.constant(tf.cast(image_greyscales, dtype=tf.int64), shape=(1, 1, 210, 160, 1), dtype=tf.int64)
label_dataset = tf.constant([0], shape=(1, 1, 1), dtype=tf.int64)
dataset = tf.data.Dataset.from_tensor_slices(( input_dataset, label_dataset ))

model = MyModel( )
optimizer = tf.keras.optimizers.Nadam( learning_rate=0.00001, beta_1=0.9, beta_2=0.999, epsilon=1e-07, name='Nadam')
lossfn = tf.keras.losses.SparseCategoricalCrossentropy( from_logits=False, reduction=tf.keras.losses.Reduction.AUTO, name='sparse_categorical_crossentropy' )
model.compile(optimizer=optimizer, loss=lossfn, metrics=['accuracy'])
model.build(input_shape=( None, 210, 160, 1 ))
model.summary()
history = model.fit( dataset, batch_size=100, epochs=5, callbacks=[custom_callback] )

prediction_result = model.predict(tf.constant(tf.cast(image_greyscales, dtype=tf.int64), shape=(1, 210, 160, 1), dtype=tf.int64))
print( prediction_result )

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
: Tasks
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
while LONG_STEPS > 0:
    ani = animation.FuncAnimation(fig, animate, interval=50, blit=True)
    plt.show()

plt.close()
Answered By: Jirayu Kaewprateep