如何修复“InvalidArgumentError”：占位符问题答案

【问题标题】：How can I fix 'InvalidArgumentError' : Placeholder problem如何修复“InvalidArgumentError”：占位符问题
【发布时间】：2019-06-02 14:16:36
【问题描述】：

我刚刚复制了tensorboard教程，为什么会出现这个错误？

InvalidArgumentError：您必须为占位符张量“y-input_6”提供一个值，其 dtype 为 float 和 shape [?,1] [[节点 y-input_6（定义于 :19）]]

这是我的代码

x_data = [[0., 0.],
          [0., 1.],
          [1., 0.],
          [1., 1.]]
y_data = [[0.],
          [1.],
          [1.],
          [0.]]
x_data = np.array(x_data, dtype=np.float32)
y_data = np.array(y_data, dtype=np.float32)`enter code here

X = tf.placeholder(tf.float32, [None, 2], name='x-input')
Y = tf.placeholder(tf.float32, [None, 1], name='y-input')

...

with tf.Session() as sess:
    # tensorboard --logdir=./logs/xor_logs
    merged_summary = tf.summary.merge_all()

    writer = tf.summary.FileWriter("./logs/xor_logs_r0_01")
    writer.add_graph(sess.graph)  # Show the graph
    # Initialize TensorFlow variables
    sess.run(tf.global_variables_initializer())

    for step in range(10001):
        summary, _ = sess.run([merged_summary, train], feed_dict={X: x_data, Y: y_data})
        writer.add_summary(summary, global_step=step)

没有merged_summary没有问题。但我需要它

 for step in range(10001):
        sess.run(train, feed_dict={X: x_data, Y: y_data})
        writer.add_summary(summary, global_step=step)

完整代码在这里

import tensorflow as tf
import numpy as np

tf.set_random_seed(777)  # for reproducibility
learning_rate = 0.01

x_data = [[0., 0.],
          [0., 1.],
          [1., 0.],
          [1., 1.]]
y_data = [[0.],
          [1.],
          [1.],
          [0.]]
x_data = np.array(x_data, dtype=np.float32)
y_data = np.array(y_data, dtype=np.float32)

X = tf.placeholder(tf.float32, [None, 2], name='x-input')
Y = tf.placeholder(tf.float32, [None, 1], name='y-input')

with tf.name_scope("layer1"):
    W1 = tf.Variable(tf.random_normal([2, 2]), name='weight1')
    b1 = tf.Variable(tf.random_normal([2]), name='bias1')
    layer1 = tf.sigmoid(tf.matmul(X, W1) + b1)

    w1_hist = tf.summary.histogram("weights1", W1)
    b1_hist = tf.summary.histogram("biases1", b1)
    layer1_hist = tf.summary.histogram("layer1", layer1)

with tf.name_scope("layer2"):
    W2 = tf.Variable(tf.random_normal([2, 1]), name='weight2')
    b2 = tf.Variable(tf.random_normal([1]), name='bias2')
    hypothesis = tf.sigmoid(tf.matmul(layer1, W2) + b2)

    w2_hist = tf.summary.histogram("weights2", W2)
    b2_hist = tf.summary.histogram("biases2", b2)
    hypothesis_hist = tf.summary.histogram("hypothesis", hypothesis)

with tf.name_scope("cost"):
    cost = -tf.reduce_mean(Y * tf.log(hypothesis) + (1 - Y) *
                           tf.log(1 - hypothesis))
    cost_summ = tf.summary.scalar("cost", cost)

with tf.name_scope("train"):
    train = tf.train.AdamOptimizer(learning_rate=learning_rate).minimize(cost)

predicted = tf.cast(hypothesis > 0.5, dtype=tf.float32)
accuracy = tf.reduce_mean(tf.cast(tf.equal(predicted, Y), dtype=tf.float32))
accuracy_summ = tf.summary.scalar("accuracy", accuracy)

with tf.Session() as sess:
    # tensorboard --logdir=./logs/xor_logs
    merged_summary = tf.summary.merge_all()

    writer = tf.summary.FileWriter("./logs/xor_logs_r0_01")
    writer.add_graph(sess.graph)  # Show the graph
    # Initialize TensorFlow variables
    sess.run(tf.global_variables_initializer())

    for step in range(10001):
        s , _ = sess.run([merged_summary, train], feed_dict={X: x_data, Y: y_data})
        writer.add_summary(summary, global_step=step)


        if step % 100 == 0:
            print(step, sess.run(cost, feed_dict={
                  X: x_data, Y: y_data}), sess.run([W1, W2]))

    h, c, a = sess.run([hypothesis, predicted, accuracy],
                       feed_dict={X: x_data, Y: y_data})
    print("\nHypothesis: ", h, "\nCorrect: ", c, "\nAccuracy: ", a)

【问题讨论】：

你没有收到这个错误：TypeError: Fetch argument None has invalid type
还有，你能把完整的代码贴出来吗？
@AnubhavSingh 好吧，不，没有这样的错误..

标签： python tensorflow tensorboard

【解决方案1】：

将此添加到代码的第一行，然后尝试运行：

tf.reset_default_graph()

像这样：

import tensorflow as tf
import numpy as np

tf.reset_default_graph()

tf.set_random_seed(777)  # for reproducibility
learning_rate = 0.01

此外，您的代码中存在错误（可能是拼写错误）。

改变

s , _ = sess.run([merged_summary, train], feed_dict={X: x_data, Y: y_data})

到

summary , _ = sess.run([merged_summary, train], feed_dict={X: x_data, Y: y_data})

【讨论】：