tensorflow运算的本质
tensorflow的运算
import tensorflow as tf
a = tf.constant(3)
b = tf.Variable(5) #常量数据
# 加减乘除操作
myadd = tf.add(a,b)
mysub = tf.subtract(a,b)
mymul = tf.multiply(a,b)
mydi = tf.divide(a,b)
init = tf.global_variables_initializer()
with tf.Session() as sess:
sess.run(init)
print("----------------------")
print("运行结果")
print(sess.run(myadd))
print(sess.run(mysub))
print(sess.run(mymul))
print(sess.run(mydi))
----------------------
运行结果
8
-2
15
0.6
assign,eval(),tf.get_default_session()介绍
import tensorflow as tf
a = tf.constant(3)
b = tf.Variable(5) #常量数据
# 加减乘除操作
myadd = tf.add(a,b)
mysub = tf.subtract(a,b)
mymul = tf.multiply(a,b)
mydi = tf.divide(a,b)
myassign = tf.assign(b,myadd)
init = tf.global_variables_initializer()
with tf.Session() as sess:
sess.run(init)
print("----------------------")
print("运行结果")
print(sess.run(myadd))
print(sess.run(mysub))
print(sess.run(mymul))
print(sess.run(mydi))
print("--------------------------")
print(sess.run(myassign))
print(myassign.eval())
print(tf.get_default_session().run(myassign))
placeholder
import tensorflow as tf
input1 = tf.placeholder(tf.float32)
input2 = tf.placeholder(tf.float32)
output = tf.multiply(input1, input2)
with tf.Session() as sess:
print("----------------------")
print("运行结果")
print(sess.run(output, feed_dict={input1:4, input2:5}))#传入的feed_dict是一个字典值
----------------------
运行结果
20.0