Python中的 numpy.argwhere()
numpy.argwhere()
函数用于查找非零数组元素的索引,按元素分组。
Syntax : numpy.argwhere(arr)
Parameters :
arr : [array_like] Input array.
Return : [ndarray] Indices of elements that are non-zero. Indices are grouped by element.
代码#1:
# Python program explaining
# argwhere() function
import numpy as geek
# input array
in_arr = [[ 2, 0, 7], [ 0, 5, 9]]
print ("Input array : ", in_arr)
out_arr = geek.argwhere(in_arr)
print ("Output indices of non zero array element: \n", out_arr)
输出:
Input array : [[2, 0, 7], [0, 5, 9]]
Output indices of non zero array element:
[[0 0]
[0 2]
[1 1]
[1 2]]
代码#2:
# Python program explaining
# argwhere() function
import numpy as geek
# input array
in_arr = geek.arange(8).reshape(4, 2)
print ("Input array : ", in_arr)
out_arr = geek.argwhere(in_arr>4)
print ("Output indices greater than 4: \n", out_arr)
输出:
Input array : [[0 1]
[2 3]
[4 5]
[6 7]]
Output indices greater than 4:
[[2 1]
[3 0]
[3 1]]