python如何增加隐藏层_TensorFlow感知器隐藏层

本篇文章帮大家学习TensorFlow感知器隐藏层,包含了TensorFlow感知器隐藏层使用方法、操作技巧、实例演示和注意事项,有一定的学习价值,大家可以用来参考。

在本章中将重点关注我们将要从已知的一组点x和f(x)中学习的网络。单个隐藏层将构建这个简单的网络。

用于解释感知器隐藏层的代码如下所示 -

#Importing the necessary modules

import tensorflow as tf

import numpy as np

import math, random

import matplotlib.pyplot as plt

np.random.seed(1000)

function_to_learn = lambda x: np.cos(x) + 0.1*np.random.randn(*x.shape)

layer_1_neurons = 10

NUM_points = 1000

#Training the parameters

batch_size = 100

NUM_EPOCHS = 1500

all_x = np.float32(np.random.uniform(-2*math.pi, 2*math.pi, (1, NUM_points))).T

np.random.shuffle(all_x)

train_size = int(900)

#Training the first 700 points in the given set x_training = all_x[:train_size]

y_training = function_to_learn(x_training)

#Training the last 300 points in the given set x_validation = all_x[train_size:]

y_validation = function_to_learn(x_validation)

plt.figure(1)

plt.scatter(x_training, y_training, c = 'blue', label = 'train')

plt.scatter(x_validation, y_validation, c = 'pink', label = 'validation')

plt.legend()

plt.show()

X = tf.placeholder(tf.float32, [None, 1], name = "X")

Y = tf.placeholder(tf.float32, [None, 1], name = "Y")

#first layer

#Number of neurons = 10

w_h = tf.Variable(

tf.random_uniform([1, layer_1_neurons], minval = -1, maxval = 1, dtype = tf.float32))

b_h = tf.Variable(tf.zeros([1, layer_1_neurons], dtype = tf.float32))

h = tf.nn.sigmoid(tf.matmul(X, w_h) + b_h)

#output layer

#Number of neurons = 10

w_o = tf.Variable(

tf.random_uniform([layer_1_neurons, 1], minval = -1, maxval = 1, dtype = tf.float32))

b_o = tf.Variable(tf.zeros([1, 1], dtype = tf.float32))

#build the model

model = tf.matmul(h, w_o) + b_o

#minimize the cost function (model - Y)

train_op = tf.train.AdamOptimizer().minimize(tf.nn.l2_loss(model - Y))

#Start the Learning phase

sess = tf.Session() sess.run(tf.initialize_all_variables())

errors = []

for i in range(NUM_EPOCHS):

for start, end in zip(range(0, len(x_training), batch_size),

range(batch_size, len(x_training), batch_size)):

sess.run(train_op, feed_dict = {X: x_training[start:end], Y: y_training[start:end]})

cost = sess.run(tf.nn.l2_loss(model - y_validation), feed_dict = {X:x_validation})

errors.append(cost)

if i%100 == 0:

print("epoch %d, cost = %g" % (i, cost))

plt.plot(errors,label='MLP Function Approximation') plt.xlabel('epochs')

plt.ylabel('cost')

plt.legend()

plt.show()

以下是功能层近似的表示(输出) -

这里有两个数据以W的形状表示。两个数据是:train和validation,它们在图例中的不同颜色表示。


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