我建立了一个简单的神经网络,只将数据分类为2类 数据是这样的
34.62365962451697,78.0246928153624,0
60.18259938620976,86.30855209546826,1
数据中没有零值,因此没有这样的成本来源。使用adagrad优化器和带梯度下降优化器的nan,成本为零 这是代码
import numpy as ny
import tensorflow as tf
def load():
data = []
for line in open("ex2data1.txt"):
row = line.split(',')
x = ny.array(row, dtype='|S4')
data.append(x.astype(ny.float64))
return ny.array(data)
def multilayer_perceptron(x, weights, biases):
# Hidden layer with ReLU activation
layer_1 = tf.add(tf.matmul(x, weights['h1']), biases['b1'])
layer_1 = tf.nn.relu(layer_1)
# Hidden layer with ReLU activation
layer_2 = tf.add(tf.matmul(layer_1, weights['h2']), biases['b2'])
layer_2 = tf.nn.relu(layer_2)
# Output layer with linear activation
out_layer = tf.matmul(layer_2, weights['out']) + biases['out']
return out_layer
# Store layers weight & bias
weights = {
'h1': tf.Variable(tf.random_normal([2, 15])),
'h2': tf.Variable(tf.random_normal([15, 15])),
'out': tf.Variable(tf.random_normal([15, 1]))
}
biases = {
'b1': tf.Variable(tf.random_normal([15])),
'b2': tf.Variable(tf.random_normal([15])),
'out': tf.Variable(tf.random_normal([1]))
}
data = load()
Xdata = ny.array(data[:, 0:2])
Ydata = ny.array(data[:, 2])
Ydata = ny.array(Ydata.reshape([100, 1]))
# Step 2 - Create input and output placeholders for data
X = tf.placeholder("float", [None, 2], name="X")
Y = tf.placeholder("float", [None, 1], name="Y")
pred = multilayer_perceptron(X, weights, biases)
# Minimize error using cross entropy
with tf.name_scope("cost"):
cost = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=pred, labels=Y))
optimizer = tf.train.AdagradOptimizer(0.001).minimize(cost)
tf.summary.scalar("cost", cost)
init = tf.global_variables_initializer()
summary_op = tf.summary.merge_all()
with tf.Session() as sess:
sess.run(init)
print(Xdata)
print(Ydata)
# Step 12 train the model
for i in range(1000):
sess.run(optimizer, feed_dict={X: Xdata, Y: Ydata})
if (i % 100 == 0):
print(sess.run(cost, feed_dict={X: Xdata, Y: Ydata}))