nn_utils.py

import tensorflow as tf
import numpy as np
import matplotlib.pyplot as plt

def load_data():
    (x_train, y_train), (x_test, y_test) = tf.keras.datasets.mnist.load_data()
    x_train = np.reshape(x_train, (x_train.shape[0], 784))/255.
    x_test = np.reshape(x_test, (x_test.shape[0], 784))/255.
    y_train = tf.keras.utils.to_categorical(y_train)
    y_test = tf.keras.utils.to_categorical(y_test)
    return (x_train, y_train), (x_test, y_test)

def plot_random_examples(x, y, p=None):
    indices = np.random.choice(range(0, x.shape[0]), 10)
    y = np.argmax(y, axis=1)
    if p is None:
        p = y
    plt.figure(figsize=(10, 5))
    for i, index in enumerate(indices):
        plt.subplot(2, 5, i+1)
        plt.imshow(x[index].reshape((28, 28)), cmap='binary')
        plt.xticks([])
        plt.yticks([])
        if y[index] == p[index]:
            col = 'g'
        else:
            col = 'r'
        plt.xlabel(str(p[index]), color=col)
    return plt

def plot_results(history):
    plt.figure(figsize=(12, 4))
    epochs = len(history['val_loss'])
    plt.subplot(1, 2, 1)
    plt.plot(range(epochs), history['val_loss'], label='Val Loss')
    plt.plot(range(epochs), history['train_loss'], label='Train Loss')
    plt.xticks(list(range(epochs)))
    plt.xlabel('Epochs')
    plt.ylabel('Loss')
    plt.legend()
    plt.subplot(1, 2, 2)
    plt.plot(range(epochs), history['val_acc'], label='Val Acc')
    plt.xticks(list(range(epochs)))
    plt.xlabel('Epochs')
    plt.ylabel('Accuracy')
    plt.legend()
    return plt