实现的第一个RNN

Posted 2021-01-28 rongye

#!/usr/bin/env python
import tensorflow as tf
from tensorflow.examples.tutorials.mnist import input_data

mnist = input_data.read_data_sets("MNIST_data",one_hot=True)

lr = 0.001
training_iters=100000
batch_size = 128

n_inputs = 28
n_steps = 28 #time steps
n_hidden_unis = 128 #neurons in hidden layer
n_classes = 10 #classes

x = tf.placeholder(tf.float32,[None,n_steps,n_inputs])
y = tf.placeholder(tf.float32,[None,n_classes])

weights = {
    #(28,128)
    ‘in‘:tf.Variable(tf.random_normal([n_inputs,n_hidden_unis])),
    #(128,10)
    ‘out‘:tf.Variable(tf.random_normal([n_hidden_unis,n_classes]))
}
biases = {
    #(128,)
    ‘in‘:tf.Variable(tf.constant(0.1,shape=[n_hidden_unis,])),
    #(10,)
    ‘out‘:tf.Variable(tf.constant(0.1,shape=[n_classes,]))
}
def RNN(X,weights,biases):
    #hidden layer for input to cell
    #X(128 batch,28 steps,28 inputs)
    #==>(128*28,28 inputs)
    X = tf.reshape(X,[-1,n_inputs])
    X_in = tf.matmul(X,weights[‘in‘])+biases[‘in‘]
    X_in = tf.reshape(X_in,[-1,n_steps,n_hidden_unis])

    #cell
    lstm_cell = tf.nn.rnn_cell.LSTMCell(n_hidden_unis,forget_bias=1.0,state_is_tuple=True)
    #lstm cell is divided into two parts(c_state,m_state)
    _init_state = lstm_cell.zero_state(batch_size,dtype=tf.float32)
    outputs,states = tf.nn.dynamic_rnn(lstm_cell,X_in,initial_state=_init_state,time_major=False)
    #tf.nn.bidirectional_dynamic_rnn(lstm_cell,X_in,_init_state)
    #tf.nn.dynamic_rnn
    #hidden layer for output as the final results
    results = tf.matmul(states[1],weights[‘out‘]) + biases[‘out‘]
    #or
    # outputs = tf.transpose(outputs,[1,0,2])
    # results = tf.matmul(outputs[-1],weights[‘out‘]) + biases[‘out‘]

    return results
pred = RNN(x,weights,biases)
cost = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits_v2( logits=pred,labels=y))
train_op = tf.train.AdamOptimizer(lr).minimize(cost)

correct_pred = tf.equal(tf.argmax(pred,1),tf.argmax(y,1))
accuracy = tf.reduce_mean(tf.cast(correct_pred,tf.float32))

init = tf.global_variables_initializer()
with tf.Session() as sess:
    sess.run(init)
    step = 0
    while step * batch_size < training_iters:
        batch_xs,batch_ys = mnist.train.next_batch(batch_size)
        batch_xs = batch_xs.reshape([batch_size,n_steps,n_inputs])
        sess.run([train_op],feed_dict={
            x:batch_xs,
            y:batch_ys,
        })
        if step % 20 == 0:
            print(sess.run(accuracy,feed_dict={
                x:batch_xs,
                y:batch_ys,
        }))
        step += 1