Tensorflow summery merge error : Shape [-1,784] has negative dimensions

Question

I am trying to get summary of a training process of the neural net below.

import tensorflow as tf 
import numpy as n         


        

Answer 1

From one comment of the deleted answer, from the original poster:

I actually build a neural net under with tf.Graph() as g. I removed the interactive session and started session as with tf.Session(g) as sess. It fixed the problem.

The graph g was not marked as the default graph that way, thus the session (tf.InteractiveSession in the original code) would use another graph instead.

Note that I stumbled upon here because of the same error message. In my case, I had accidentally something like this:

input_data = tf.placeholder(tf.float32, shape=(None, 50))
input_data = tf.tanh(input_data)
session.run(..., feed_dict={input_data: ...})

I.e. I didn't feed the placeholder. It seems that some other tensor operations can then result in this confusing error as internally an undefined dimension is represented as -1.