Python numpy.isinf()用法及代碼示例

關於：
numpy.isinf(array [，out])：逐個測試是否為+ ve或-ve無限，是否將​​結果作為布爾數組返回。
參數：

array:[array_like]Input array or object whose 
         elements, we need to test for  infinity
out  :[ndarray, optional]Output array placed 
        with result. Its type is preserved and
        it  must be of the right shape to hold 
         the output.

返回：

boolean array containing the result. For scalar 
input, the result is a new boolean with value
True if the input is positive or negative infinity; 
otherwise the value is False. For array input, the 
result is a boolean array with the same shape as 
the input and the values are True where the 
corresponding element of the input is positive
or negative infinity; elsewhere the values are False.

代碼1：

# Python Program illustrating 
# numpy.isinf() method 
   
import numpy as geek  
  
print("Finite:", geek.isinf(1), "\n") 
  
print("Finite:", geek.isinf(0), "\n") 
  
# not a number 
print("Finite:", geek.isinf(geek.nan), "\n") 
  
#  infinity 
print("Finite:", geek.isinf(geek.inf), "\n") 
  
print("Finite:", geek.isinf(geek.NINF), "\n")  
  
x = geek.array([-geek.inf, 0., geek.inf]) 
y = geek.array([2, 2, 2]) 
print("Checking for infinity:", geek.isinf(x, y)) 

輸出：

Finite: False 

Finite: False 

Finite: False 

Finite: True 

Finite: True 

Checking for infinity: [1 0 1]

代碼2：

# Python Program illustrating 
# numpy.isinf() method 
    
import numpy as geek  
   
# Returns True/False value for each element  
b = geek.arange(8).reshape(2, 4) 
                 
print("\n",b) 
print("\nIs Infifnity:\n", geek.isinf(b)) 
  
# geek.inf :Positive Infinity 
# geek.NINF:negative Infinity 
b = [[geek.inf],  
     [geek.NINF]] 
print("\nIs Infifnity:\n", geek.isinf(b))

輸出：

 [[0 1 2 3]
 [4 5 6 7]]

Is Infifnity:
 [[False False False False]
 [False False False False]]

Is Infifnity:
 [[ True]
 [ True]]

參考文獻：
https://docs.scipy.org/doc/numpy-dev/reference/generated/numpy.isinf.html#numpy.isinf