在Tensorflow中,如何根据索引在Tensor中分配值? [英] In Tensorflow, how to assign values in Tensor according to the indices?
问题描述
我想根据索引分配张量值。
I want to assign values in a tensor according to the indices.
例如,
根据池值和<一个href = https://www.tensorflow.org/versions/r0.9/api_docs/python/nn.html#max_pool_with_argmax> tf.nn.max_pool_with_argmax ,我想将这些合并值放回
For example, According to the pooling values and the corresponding indices output of tf.nn.max_pool_with_argmax, I want to put these pooling values back into the original unpooling Tensor with the indices.
我发现 tf.nn.max_pool_with_argmax
的输出索引是平坦的。
一个问题:如何将它们重新分解成Tensorflow中的坐标?
I find the output indices of tf.nn.max_pool_with_argmax
is flattened.
One question: How to unravel them back into the coordinates in Tensorflow?
另一个问题:如何将合并张量的每个值分配给Tensorflow中的位置
Another question: How to assign each value of the pooling tensor to the position of the original unpooling tensor in Tensorflow, given the indices?
非常感谢你。
我试图使代码来实现这一点,但是我只能使用 numpy
。在 tf.nn.max_pool_with_argmax
并分配到Tensorflow的解压缩张量之后,我不怎么获得平坦的索引。
I tried to make the codes to achieve that, but I can just use numpy
. I do not how to obtain the flattened indices after the tf.nn.max_pool_with_argmax
and assigning into the unpooling tensor in Tensorflow.
ksize = 3
stride = 1
input_image = tf.placeholder(tf.float32, name='input_image')
#conv1
kernel = tf.Variable(tf.truncated_normal([ksize, ksize, 3, 16],stddev=0.1),
name='kernel')
conv = tf.nn.conv2d(input_image, kernel, [1,stride,stride,1], padding='SAME')
biases = tf.Variable(tf.constant(0.0, shape = [16]), name = 'biases')
bias = tf.nn.bias_add(conv, biases)
conv1 = tf.nn.relu(bias, name='conv1')
#pool1
pool1, pool1_indices = tf.nn.max_pool_with_argmax(conv1, ksize=[1, 2, 2, 1],
strides=[1, 2, 2, 1],
padding='SAME', name='pool1')
#upsample by assigning the values of pool1 to the position in unpooling Tensor according to pool1_indices
indices = pool1_indices
unravel_pool1_indices = np.unravel_index(indices,[4,32,32,16])
unravel_pool1_coordinates = np.array(unravel_pool1_indices)
coor_shape = np.shape(unravel_pool1_coordinates)
unravel_pool1_coordinates = np.reshape(unravel_pool1_coordinates,(coor_shape[0],coor_shape[1]*coor_shape[2]*coor_shape[3]*coor_shape[4]))
unravel_pool1_coordinates = unravel_pool1_coordinates.T
values = pool1
values = np.reshape(values,(np.size(values)))
up1 = tf.constant(0.0, shape = [4,32,32,16])
delta = tf.SparseTensor(unravel_pool1_coordinates, values, shape = [4,32,32,16])
result = up1 + tf.sparse_tensor_to_dense(delta)
with tf.Session() as session:
session.run(tf.initialize_all_variables())
test_image = np.random.rand(4,32,32,3)
sess_outputs = session.run([pool1, pool1_indices],
{input_image.name: test_image})
推荐答案
同一问题在 tf.unravel_index中列出(原为:tf.argmin,所有维度)#2075
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