In Tensorflow, how to use tf.gather() for the last dimension?

Question

I am trying to gather slices of a tensor in terms of the last dimension for partial connection between layers. Because the output tensor\'s shape is [batch_size, h, w,

Answer 1

Tensor doesn't have attribute shape, but get_shape() method. Below is runnable by Python 2.7

import tensorflow as tf
import numpy as np
x = tf.constant([[1, 2, 3],
                 [4, 5, 6],
                 [7, 8, 9]])
idx = tf.constant([1, 0, 2])
idx_flattened = tf.range(0, x.get_shape()[0]) * x.get_shape()[1] + idx
y = tf.gather(tf.reshape(x, [-1]),  # flatten input
              idx_flattened)  # use flattened indices

with tf.Session(''):
  print y.eval()  # [2 4 9]