Python中的 numpy.eye()

numpy.eye(R, C = None, k = 0, dtype = type <'float'>) : – eye 工具返回一个二维数组，其中对角线为1 ，其他位置为0 。对角线可以是 main、upper 或 lower，具体取决于可选参数k 。正k用于上对角线，负k用于下对角线， 0 k （默认）用于主对角线。

参数 ：

R : Number of rows
C : [optional] Number of columns; By default M = N
k : [int, optional, 0 by default]
          Diagonal we require; k>0 means diagonal above main diagonal or vice versa.
dtype : [optional, float(by Default)] Data type of returned array.  

返回：

array of shape, R x C, an array where all elements 
are equal to zero, except for the k-th diagonal, 
whose values are equal to one.

例子：

Python

# Python Programming illustrating
# numpy.eye method
 
import numpy as geek
 
# 2x2 matrix with 1's on main diagonal
b = geek.eye(2, dtype = float)
print("Matrix b : \n", b)
 
# matrix with R=4 C=5 and 1 on diagonal
# below main diagonal
a = geek.eye(4, 5, k = -1)
print("\nMatrix a : \n", a)

输出 ：

Matrix b : 
 [[ 1.  0.]
 [ 0.  1.]]

Matrix a : 
 [[ 0.  0.  0.  0.  0.]
 [ 1.  0.  0.  0.  0.]
 [ 0.  1.  0.  0.  0.]
 [ 0.  0.  1.  0.  0.]]

笔记 ：
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