手書きデジタル識別------softmax回帰モデル公式ケースコメント(Tensorflow,Pythonに基づく)
10210 ワード
# ----Softmax
# regression
import os
import tensorflow as tf
from tensorflow.examples.tutorials.mnist import input_data
data = input_data.read_data_sets("/tmp/data/", one_hot=True) # mnist , Numpy 、 、 。
# 。
# :
# 1、 ( ) ,
# ( softmax , ),
# 。
# 2、softmax : ( , , softmax )
# :
# ① ,
# x, i
# evidencei =∑i(wi, jxj) + bi
# evidence_i =∑_i(w_{i, j}x_j)+b_ievidencei=∑i(wi, jxj) + bi
# ② softmax evidence ,
# y = softmax(evidence)
# y = softmax(evidence)
# y = softmax(evidence)
# ,
#
# y = softmax(Wx + b)
# y = softmax(Wx + b)
# y = softmax(Wx + b)
# 3、 python ,TensorFlow , , python 。
# placeholder :
# ---------------------
# :Crystal
# :CSDN
# :https: // blog.csdn.net / weixin_43226400 / article / details / 82749769
# : , !
#http://www.cnblogs.com/rgvb178/p/6052541.html
# Softmax Regression Model Softmax
def regression(x):
W = tf.Variable(tf.zeros([784, 10]), name="W")
b = tf.Variable(tf.zeros([10]), name="b")
y = tf.nn.softmax(tf.matmul(x, W) + b)
# print(y)
return y, [W, b]
# model
with tf.variable_scope("regression"):
x = tf.placeholder(tf.float32, [None, 784])
y, variables = regression(x)
# (cross - entropy) ,
# Hy′(y) =−∑iy′ilog(yi)
# y ,y’ ( , one - hotvector)
# train
y_ = tf.placeholder("float", [None, 10])
#
cross_entropy = -tf.reduce_sum(y_ * tf.log(y))
# tensorflow ,
train_step = tf.train.GradientDescentOptimizer(0.01).minimize(cross_entropy)
# tf.argmax , ,
correct_prediction = tf.equal(tf.argmax(y, 1), tf.argmax(y_, 1))
# equal , cast
accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))
saver = tf.train.Saver(variables)
with tf.Session() as sess:
#
sess.run(tf.global_variables_initializer())
for _ in range(10000):
batch_xs, batch_ys = data.train.next_batch(100)
# , 100 batch
sess.run(train_step, feed_dict={x: batch_xs, y_: batch_ys})
#
print(sess.run(accuracy, feed_dict={x: data.test.images, y_: data.test.labels}))
#
# print(os.path.join(os.path.dirname(__file__), 'data', 'regression.ckpt'))
# // :'mnist/data/regression.ckpt'
path = saver.save(
sess, 'mnist/data/regression.ckpt',
write_meta_graph=False, write_state=False)
print("Saved:", path)
# path = saver.save(
# sess, os.path.join(os.path.dirname(__file__), 'mnist\data', 'regression.ckpt'),write_meta_graph=False, write_state=False)
# print("Saved:", path) write_meta_graph=False, write_state=False)
print("Saved:", path)
# path = saver.save(
# sess, os.path.join(os.path.dirname(__file__), 'mnist\data', 'regression.ckpt'),write_meta_graph=False, write_state=False)
# print("Saved:", path)