根据部分和添加填充

Question

我有四个给定变量：

团体人数
组总数
部分总和
一维张量当组内的总和达到部分总和时，我想添加零。例如：

groupsize = 4
totalgroups = 3
partialsum = 15
d1tensor = torch.tensor([ 3, 12,  5,  5,  5,  4, 11])

预期结果是： [ 3, 12, 0, 0, 5, 5, 5, 0, 4, 11, 0, 0]

我不知道如何在纯 pytorch 中实现它。在 python 中会是这样的：

target = [0]*(groupsize*totalgroups)

cursor = 0
current_count = 0
d1tensor = [ 3, 12,  5,  5,  5,  4, 11]

for idx, ele in enumerate(target):
  subgroup_start = (idx//groupsize) *groupsize
  subgroup_end = subgroup_start + groupsize 
  if sum(target[subgroup_start:subgroup_end]) < partialsum: 
     target[idx] = d1tensor[cursor]
     cursor +=1

有人可以帮我吗？我已经用谷歌搜索了，但找不到任何东西。

Answer 1

这里有一些逻辑、Numpy 和列表理解就足够了。我会一步一步分解，你可以把它变得更苗条更漂亮：

import numpy as np

my_val = 15
block_size = 4
total_groups = 3
d1 = [3, 12,  5,  5,  5,  4, 11]
d2 = np.cumsum(d1)
d3 = d2 % my_val == 0 #find where sum of elements is 15 or multiple
split_points= [i+1 for i, x in enumerate(d3) if x] # find index where cumsum == my_val
#### Option 1
split_array = np.split(d1, split_points, axis=0)
padded_arrays = [np.pad(array, (0, block_size - len(array)), mode='constant') for array in split_array] #pad arrays
padded_d1 = np.concatenate(padded_arrays[:total_groups]) #put them together, discard extra group if present
#### Option 2
split_points = [el for el in split_points if el <len(d1)] #make sure we are not splitting on the last element of d1
split_array = np.split(d1, split_points, axis=0)
padded_arrays = [np.pad(array, (0, block_size - len(array)), mode='constant') for array in split_array] #pad arrays
padded_d1 = np.concatenate(padded_arrays)

根据部分和添加填充

Add padding based on partial sum

python

pytorch

tensor