不做卷积,只是增加多层神经网络层。

#-*- encoding:utf-8 -*-
#!/usr/local/env python import numpy as np
import tensorflow as tf
from tensorflow.examples.tutorials.mnist import input_data def add_layer(inputs, in_size, out_size, activation_function=None):
W = tf.Variable(tf.random_normal([in_size, out_size]))
b = tf.Variable(tf.zeros([1, out_size]) + 0.01) Z = tf.matmul(inputs, W) + b
if activation_function is None:
outputs = Z
else:
outputs = activation_function(Z) return outputs if __name__ == "__main__": MNIST = input_data.read_data_sets("mnist", one_hot=True) learning_rate = 0.01
batch_size = 128
n_epochs = 70 X = tf.placeholder(tf.float32, [batch_size, 784])
Y = tf.placeholder(tf.float32, [batch_size, 10]) layer_dims = [784, 500, 500, 10]
layer_count = len(layer_dims)-1 # 不算输入层
layer_iter = X for l in range(1, layer_count): # layer [1,layer_count-1] is hidden layer
layer_iter = add_layer(layer_iter, layer_dims[l-1], layer_dims[l], activation_function=tf.nn.relu)
prediction = add_layer(layer_iter, layer_dims[layer_count-1], layer_dims[layer_count], activation_function=None) entropy = tf.nn.softmax_cross_entropy_with_logits(labels=Y, logits=prediction)
loss = tf.reduce_mean(entropy) optimizer = tf.train.GradientDescentOptimizer(learning_rate).minimize(loss) init = tf.initialize_all_variables() with tf.Session() as sess:
sess.run(init) n_batches = int(MNIST.test.num_examples/batch_size)
for i in range(n_epochs):
for j in range(n_batches):
X_batch, Y_batch = MNIST.train.next_batch(batch_size)
_, loss_ = sess.run([optimizer, loss], feed_dict={X: X_batch, Y: Y_batch})
if i % 10 == 5 and j == 0:
print( "Loss of epochs[{0}]: {1}".format(i, loss_)) # test the model
n_batches = int(MNIST.test.num_examples/batch_size)
total_correct_preds = 0
for i in range(n_batches):
X_batch, Y_batch = MNIST.test.next_batch(batch_size)
preds = sess.run(prediction, feed_dict={X: X_batch, Y: Y_batch})
correct_preds = tf.equal(tf.argmax(preds, 1), tf.argmax(Y_batch, 1))
accuracy = tf.reduce_sum(tf.cast(correct_preds, tf.float32)) total_correct_preds += sess.run(accuracy) print ("Accuracy {0}".format(total_correct_preds/MNIST.test.num_examples))
05-11 22:17