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原始GAN对抗网络

原始GAN对抗网络

作者: Kean_L_C | 来源:发表于2018-10-27 20:21 被阅读87次

    参考

    简单GAN实现

    • 利用GAN生成图片,曲线(pytorch), minst(tensorflow)。

    pytorch(莫凡大神课程)

    # -*- coding: utf-8 -*-
    # @Time    : 2018/10/14 22:42
    # @Author  : kean
    # @Email   : 
    # @File    : gan_morvan.py
    # @Software: PyCharm
    
    
    """
    View more, visit my tutorial page: https://morvanzhou.github.io/tutorials/
    My Youtube Channel: https://www.youtube.com/user/MorvanZhou
    Dependencies:
    torch: 0.4
    numpy
    matplotlib
    """
    import torch
    import torch.nn as nn
    import numpy as np
    import matplotlib.pyplot as plt
    
    # torch.manual_seed(1)    # reproducible
    # np.random.seed(1)
    
    # Hyper Parameters
    BATCH_SIZE = 64
    LR_G = 0.0001           # learning rate for generator
    LR_D = 0.0001           # learning rate for discriminator
    N_IDEAS = 5             # think of this as number of ideas for generating an art work (Generator)
    ART_COMPONENTS = 15     # it could be total point G can draw in the canvas
    PAINT_POINTS = np.vstack([np.linspace(-1, 1, ART_COMPONENTS) for _ in range(BATCH_SIZE)])
    
    # show our beautiful painting range
    # plt.plot(PAINT_POINTS[0], 2 * np.power(PAINT_POINTS[0], 2) + 1, c='#74BCFF', lw=3, label='upper bound')
    # plt.plot(PAINT_POINTS[0], 1 * np.power(PAINT_POINTS[0], 2) + 0, c='#FF9359', lw=3, label='lower bound')
    # plt.legend(loc='upper right')
    # plt.show()
    
    
    def artist_works():     # painting from the famous artist (real target)
        a = np.random.uniform(1, 2, size=BATCH_SIZE)[:, np.newaxis]
        paintings = a * np.power(PAINT_POINTS, 2) + (a-1)
        paintings = torch.from_numpy(paintings).float()
        return paintings
    
    G = nn.Sequential(                      # Generator
        nn.Linear(N_IDEAS, 128),            # random ideas (could from normal distribution)
        nn.ReLU(),
        nn.Linear(128, ART_COMPONENTS),     # making a painting from these random ideas
    )
    
    D = nn.Sequential(                      # Discriminator
        nn.Linear(ART_COMPONENTS, 128),     # receive art work either from the famous artist or a newbie like G
        nn.ReLU(),
        nn.Linear(128, 1),
        nn.Sigmoid(),                       # tell the probability that the art work is made by artist
    )
    
    opt_D = torch.optim.Adam(D.parameters(), lr=LR_D)
    opt_G = torch.optim.Adam(G.parameters(), lr=LR_G)
    
    plt.ion()   # something about continuous plotting
    
    for step in range(10000):
        artist_paintings = artist_works()           # real painting from artist
        G_ideas = torch.randn(BATCH_SIZE, N_IDEAS)  # random ideas
        G_paintings = G(G_ideas)                    # fake painting from G (random ideas)
    
        prob_artist0 = D(artist_paintings)          # D try to increase this prob
        prob_artist1 = D(G_paintings)               # D try to reduce this prob
    
        D_loss = - torch.mean(torch.log(prob_artist0) + torch.log(1. - prob_artist1))
        G_loss = torch.mean(torch.log(1. - prob_artist1))
    
        opt_D.zero_grad()
        D_loss.backward(retain_graph=True)      # reusing computational graph
        opt_D.step()
    
        opt_G.zero_grad()
        G_loss.backward()
        opt_G.step()
    
        if step % 50 == 0:  # plotting
            plt.cla()
            plt.plot(PAINT_POINTS[0], G_paintings.data.numpy()[0], c='#4AD631', lw=3, label='Generated painting',)
            plt.plot(PAINT_POINTS[0], 2 * np.power(PAINT_POINTS[0], 2) + 1, c='#74BCFF', lw=3, label='upper bound')
            plt.plot(PAINT_POINTS[0], 1 * np.power(PAINT_POINTS[0], 2) + 0, c='#FF9359', lw=3, label='lower bound')
            plt.text(-.5, 2.3, 'D accuracy=%.2f (0.5 for D to converge)' % prob_artist0.data.numpy().mean(), fontdict={'size': 13})
            plt.text(-.5, 2, 'D score= %.2f (-1.38 for G to converge)' % -D_loss.data.numpy(), fontdict={'size': 13})
            plt.ylim((0, 3))
            plt.legend(loc='upper right', fontsize=10)
            plt.draw()
            plt.pause(0.01)
    
    plt.ioff()
    plt.show()
    

    tensorflow(错误之处帮忙指出)

    # -*- coding: utf-8 -*-
    # @Time    : 2018/10/27 17:18
    # @Author  : kean
    # @Email   : 
    # @File    : simple_gan.py
    # @Software: PyCharm
    
    import tensorflow as tf
    from tensorflow.examples.tutorials.mnist import input_data
    import numpy as np
    import matplotlib.pyplot as plt
    import matplotlib.gridspec as gridspec
    import os
    
    mnist = input_data.read_data_sets("D:/data/minst/", one_hot=True)
    
    
    class Net:
        def __init__(self):
            # discrininator
            # real input
            self.x_input = tf.placeholder(shape=[None, 784], dtype=tf.float32, name="x_input")
            # input_layer
            self.d_input_weight, self.d_input_bias = self.init(shape=[784, 128], name="d_input")
            # hidden 1
            self.d_h1_weight, self.d_h1_bias = self.init(shape=[128, 1], name="d_h1")  # full connection layer
    
            # generator
            # fake idea
            self.idea = tf.placeholder(shape=[None, 10], dtype=tf.float32, name="idea")
            self.g_input_weight, self.g_input_bias = self.init(shape=[10, 128], name="g_input")
            self.g_h1_weight, self.g_h1_bias = self.init(shape=[128, 784], name="g_h1")
    
            # optimazer
            self.fake = self.generator()
            self.d_loss, self.g_loss = self.loss()
            self.d_optimazer = tf.train.AdamOptimizer(learning_rate=0.0001).minimize(self.d_loss)
            self.g_optimazer = tf.train.AdamOptimizer(learning_rate=0.0001).minimize(self.g_loss)
    
            sess = tf.Session()
            sess.run(tf.global_variables_initializer())
            self.sess = sess
    
    
        def generator(self):
            g_h1_accept = tf.nn.relu(tf.matmul(self.idea, self.g_input_weight) + self.g_input_bias, name="g_h1_accept")
            # print("g_input_weight", self.g_input_weight)
            # print("g_input_bias", self.g_input_bias)
            # print("g_h1_accept", g_h1_accept)
            fake = tf.nn.sigmoid(tf.matmul(g_h1_accept, self.g_h1_weight) + self.g_h1_bias, name="fake")
            # print("fake", fake)
            return fake
    
        def disciminator(self, x_input):
            """
            :return: 0-1
            """
            d_h1_accept = tf.nn.relu(tf.matmul(x_input, self.d_input_weight) + self.d_input_bias)
            logits = tf.matmul(d_h1_accept, self.d_h1_weight) + self.d_h1_bias
            scores = tf.nn.sigmoid(logits)
            return scores, logits
    
        def loss(self):
            real_scores, real_logits = self.disciminator(self.x_input)
            fake_scores, fake_logits = self.disciminator(self.fake)
            # 尽可能区分真伪,real_scores->1,fake_scores->0, optimazer.min
            d_loss = - tf.reduce_mean(tf.math.log(tf.clip_by_value(real_scores, 1e-8, 1)) +
                                      tf.math.log(tf.clip_by_value(1 - fake_scores, 1e-8, 1)), name="d_loss")
            # 尽可能让判别器错误, fake_scores越接近1越好,optimazer.min
            g_loss = - tf.reduce_mean(tf.math.log(tf.clip_by_value(fake_scores, 1e-8, 1)), name="g_loss")
            return d_loss, g_loss
    
        def train(self, num_show=2000, batch_size=64):
            count = 1
            while True:
                batch, _ = mnist.train.next_batch(batch_size)
                idea = np.random.randn(batch_size, 10)
                _, d_loss = self.sess.run([self.d_optimazer, self.d_loss],
                                          feed_dict={self.x_input: batch, self.idea: idea}
                                          )
                _, g_loss = self.sess.run([self.g_optimazer, self.g_loss],
                                          feed_dict={self.idea: idea}
                                          )
                if count % num_show == 0:
                    print("%d loss: (%.5f, %.5f)" % (count, d_loss, g_loss))
                    fake = self.sess.run([self.fake], {self.idea: np.random.randn(1, 10)})
                    fig = self.plot(fake)
                    fig.show()
                    plt.pause(1)
                    plt.close()
                count += 1
    
    
    
    
        def init(self, shape, name):
            weight = tf.Variable(initial_value=tf.random_uniform(shape=shape, minval=-1, maxval=1), name=name + "_weight")
            bias = tf.Variable(initial_value=tf.zeros(shape=[1, shape[-1]]), dtype=tf.float32, name=name + "_bias")
            return weight, bias
    
        def plot(self, samples):
            fig = plt.figure(figsize=(4, 4))
            gs = gridspec.GridSpec(4, 4)
            gs.update(wspace=0.05, hspace=0.05)
    
            for i, sample in enumerate(samples):
                ax = plt.subplot(gs[i])
                plt.axis('off')
                ax.set_xticklabels([])
                ax.set_yticklabels([])
                ax.set_aspect('equal')
                plt.imshow(sample.reshape(28, 28), cmap='Greys_r')
            return fig
    
    
    
    if __name__ == '__main__':
        net = Net()
        net.train(num_show=1000)
    

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          本文标题:原始GAN对抗网络

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