python - 无法确定 NumPy 数组的切片索引

Question

我有一个 X * Y 的 NumPy 数组元素，表示为扁平数组 ( arr = np.array(x * y) )。
给定以下值:

X = 832
Y = 961

我需要按以下顺序访问数组的元素:

arr[0:832:2]
arr[1:832:2]
arr[832:1664:2]
arr[833:1664:2]
...
arr[((Y-1) * X):(X * Y):2]

从数学上讲，我不确定如何实现 start和 stop对于循环中的每次迭代。

Answer 1

This should do the trick

Y = 961
X = 832

all_ = np.random.rand(832*961)

# Iterating over the values of y
for i in range(1,Y):
    # getting the indicies from the array we need
    # i - 1 = Start
    # X*i = END
    # 2 is the step
    indicies = list(range(i-1,X*i,2))
    # np.take slice values from the array or get values corresponding to the list of indicies we prepared above
    required_array = np.take(indices=indices)