减少张量流中的矩阵数组

Question

tf.reduce_mean和tf.reduce_prod等函数执行元素操作以减少沿轴的张量。我有一个形状为R的张量(1000, 3, 3)，一个3x3矩阵列表。我想要做的是矩阵将它们相乘，所以我保持一个3x3矩阵。如果这是numpy我可以使用

np.linalg.multi_dot(R)

我怎么能在张量流中做到这一点？

Answer 1

您可以使用tf.scan：tf.scan(lambda a, b: tf.matmul(a, b), R)[-1]

import tensorflow as tf
import numpy as np

R = np.random.rand(10, 3, 3)
R_reduced = np.linalg.multi_dot(R)

R_reduced_t = tf.scan(lambda a, b: tf.matmul(a, b), R)[-1]

with tf.Session() as sess:
  R_reduced_val = sess.run(R_reduced_t)
  diff = R_reduced_val - R_reduced
  print(diff)

打印：

[[ -3.55271368e-15   0.00000000e+00   0.00000000e+00]
 [  1.77635684e-15   0.00000000e+00   3.55271368e-15]
 [ -1.77635684e-15   3.55271368e-15   0.00000000e+00]]