Matrix diagonals

Matrices that are diagonal in nature consist mostly of zeros and have non-zero entries only along the main diagonal. Not all diagonal matrices need to be square.

Using the diagonal part operation, we can get the diagonal of a given matrix, and to create a matrix with a given diagonal, we use the diag operation from tensorflow. The following example shows how to use diagonal operators on tensor objects:

import tensorflow as tf
 
mat = tf.constant([
 [0, 1, 2],
 [3, 4, 5],
 [6, 7, 8]
], dtype=tf.float32)
 
# get diagonal of the matrix
diag_mat = tf.diag_part(mat)
 
# create matrix with given diagonal
mat = tf.diag([1,2,3,4])
 
with tf.Session() as sess:
   print(sess.run(diag_mat))
   print(sess.run(mat))

The output of this is shown as follows:

 [ 0.  4.  8.]
[[1 0 0 0][0 2 0 0] [0 0 3 0] [0 0 0 4]]