How to create a Rotation Matrix in Tensorflow

with two operations:

def rotate(tf, points, theta):
    rotation_matrix = tf.pack([tf.cos(theta),
                              -tf.sin(theta),  
                               tf.sin(theta),
                               tf.cos(theta)])
    rotation_matrix = tf.reshape(rotation_matrix, (2,2))
    return tf.matmul(points, rotation_matrix)

To answer the question of 'How to build a Rotation Matrix', the following is cleaner than requiring a multiple pack (stack) calls:

tf.stack([(tf.cos(angle), -tf.sin(angle)), (tf.sin(angle), tf.cos(angle))], axis=0)