Python numpy.tri()用法及代碼示例

numpy.tri(R，C = None，k = 0，dtype ='float')：創建一個數組，數組在給定的對角線(約k)處和對角線以下(小於k)，在其他位置為0。
參數：

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

# Python Program illustrating 
# numpy.tri method 
  
import numpy as geek 
  
print("tri with k = 1 : \n",geek.tri(2, 3, 1, dtype = float), "\n") 
  
print("tri with main diagonal : \n",geek.tri(3, 5, 0), "\n") 
  
print("tri with k = -1 : \n",geek.tri(3, 5, -1), "\n")

輸出：

tri with k = 1 : 
 [[ 1.  1.  0.]
 [ 1.  1.  1.]] 

tri with main diagonal : 
 [[ 1.  0.  0.  0.  0.]
 [ 1.  1.  0.  0.  0.]
 [ 1.  1.  1.  0.  0.]] 

tri with k = -1 : 
 [[ 0.  0.  0.  0.  0.]
 [ 1.  0.  0.  0.  0.]
 [ 1.  1.  0.  0.  0.]]