CODEWITHSUNDEEP
pythontensorflow
jinyangzhang
jinyangzhang

Reputation: 3

"ValueError: setting an array element with a sequence." TensorFlow

I tried to explore a simple demo，but got this error. How could I modify my code?

import tensorflow as tf

sess = tf.Session()

x_ = tf.Variable([[-9,6,-2,3], [-4,3,-1,10]], dtype=tf.float32)
x = tf.placeholder(tf.float32, shape=[4,2])
y = tf.nn.relu(x)

sess.run(tf.global_variables_initializer())
print(sess.run(x_))
print(sess.run(y,feed_dict={x:x_}))

The output I get is:

[[ -9.   6.  -2.   3.]
 [ -4.   3.  -1.  10.]]

Traceback (most recent call last):
  File "C:\Users\jy\Documents\NetSarang\Xftp\Temporary\test.py", line 19, in <module>
    print(sess.run(y,feed_dict={x:x_}))
  File "C:\Program Files\Anaconda3\lib\site-packages\tensorflow\python\client\session.py", line 767, in run
    run_metadata_ptr)
  File "C:\Program Files\Anaconda3\lib\site-packages\tensorflow\python\client\session.py", line 938, in _run
    np_val = np.asarray(subfeed_val, dtype=subfeed_dtype)
  File "C:\Program Files\Anaconda3\lib\site-packages\numpy\core\numeric.py", line 482, in asarray
    return array(a, dtype, copy=False, order=order)
ValueError: setting an array element with a sequence.

Upvotes: 0

Views: 2455

Answers (1)

Michael0x2a
Michael0x2a

Reputation: 63978

First, the dimensionality of your x_ variable wrong: currently, it's of shape [2, 4], but you're attempting to use it in a slot that's expecting data of shape [4, 2].

Second, tf.Variable is meant to represent literally a variable (in the mathematical sense) within your neural net model that'll be tuned as you train your model -- it's a mechanism for maintaining state.

To provide actual input to train your model, you can simply pass in a regular Python array (or numpy array) instead.

Here's a fixed version of your code that appears to do what you want:

import tensorflow as tf

sess = tf.Session()

x = tf.placeholder(tf.float32, shape=[4,2])
y = tf.nn.relu(x)
sess.run(tf.global_variables_initializer())

x_ = [[-9, -4], [6, 3], [-2, -1], [3, 10]]
print(sess.run(y, feed_dict={x:x_}))

If you really did want a node within your neural net to start off initialized with those values, I'd get rid of the placeholder and use x_directly:

import tensorflow as tf

sess = tf.Session()

x = tf.Variable([[-9, -4], [6, 3], [-2, -1], [3, 10]], dtype=tf.float32)
y = tf.nn.relu(x)
sess.run(tf.global_variables_initializer())

print(sess.run(y))

This is probably not what you meant to do, though -- it's sort of unusual to have a model that doesn't accept any input.

Upvotes: 1

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