Ch `02`: Concept `02`

Evaluating ops

Import TensorFlow:



In [1]:

    
import tensorflow as tf

Start with a 1x2 matrix:



In [2]:

    
x = tf.constant([[1, 2]])

Let's negate it. Define the negation op to be run on the matrix:



In [4]:

    
neg_x = tf.negative(x)

It's nothing special if you print it out. In fact, it doesn't even perform the negation computation. Check out what happens when you simply print it:



In [16]:

    
print(neg_x)









    



Tensor("Neg_3:0", shape=(1, 2), dtype=int32)

You need to summon a session so you can launch the negation op:



In [17]:

    
with tf.Session() as sess:
    result = sess.run(neg_x)
    print(result)









    



[[-1 -2]]