numpy.fromfunction()函数Python

numpy.fromfunction()函数通过在每个坐标上执行一个函数来构造一个数组，因此，结果数组在坐标 (x, y, z) 处具有值 fn(x, y, z)。

Syntax : numpy.fromfunction(function, shape,  dtype)

Parameters :

function : [callable] The function is called with N parameters, where N is the rank of shape. Each parameter represents the coordinates of the array varying along a specific axis.

shape : [(N, ) tuple of ints] Shape of the output array, which also determines the shape of the coordinate arrays passed to function.

dtype : [data-type, optional] Data-type of the coordinate arrays passed to function.

Return : The output array.

代码#1：

Python3

# Python program explaining
# numpy.fromfunction() function
    
# importing numpy as geek
import numpy as geek
    
gfg = geek.fromfunction(lambda i, j: i * j, (4, 4), dtype = float)
    
print(gfg)

输出 ：

[[0. 0. 0. 0.]

[0. 1. 2. 3.]

[0. 2. 4. 6.]

[0. 3. 6. 9.]]

代码#2：

Python3

# Python program explaining
# numpy.fromfunction() function
    
# importing numpy as geek
import numpy as geek
    
gfg = geek.fromfunction(lambda i, j: i == j, (3, 3), dtype = int)
    
print(gfg)

输出 ：

[[ True False False]

[False True False]

[False False True]]