[tensorflow] tf.gather使用方法

tf.gather：用一個一維的索引數組，將張量中對應索引的向量提取出來

import tensorflow as tf 

a = tf.Variable([[1,2,3,4,5], [6,7,8,9,10], [11,12,13,14,15]])
index_a = tf.Variable([0,2])

b = tf.Variable([1,2,3,4,5,6,7,8,9,10])
index_b = tf.Variable([2,4,6,8])

with tf.Session() as sess:
    sess.run(tf.global_variables_initializer())
    print(sess.run(tf.gather(a, index_a)))
    print(sess.run(tf.gather(b, index_b)))

#  [[ 1  2  3  4  5]
#   [11 12 13 14 15]]

#  [3 5 7 9]