Python| Numpy np.polyfromroots() 方法

np.polyfromroots()方法用于生成具有给定根的多项式序列。

Syntax : np.polyfromroots(roots)
Parameters:
roots :[array_like] Input sequence containing the roots.

Return : [ndarray] 1-D array of coefficients of polynomial series.

代码#1：

# Python program explaining
# numpy.polyfromroots() method 
    
# importing numpy as np  
# and numpy.polynomial.polynomial module as geek 
import numpy as np 
import numpy.polynomial.polynomial as geek
    
# Input roots
  
roots = (2, 4, 8) 
     
# using np.polyfromroots() method 
res = geek.polyfromroots(roots) 
  
# Resulting polynomial series coefficient
print (res) 

输出：

[-64.  56. -14.   1.]

代码#2：

# Python program explaining
# numpy.polyfromroots() method 
    
# importing numpy as np  
# and numpy.polynomial.polynomial module as geek 
import numpy as np 
import numpy.polynomial.polynomial as geek
    
# Input roots
s = (1, 2, 3, 4, 5) 
  
    
# using np.polyfromroots() method 
res = geek.polyfromroots(s) 
  
# Resulting polynomial series coefficient
print (res) 

输出：

[-120.  274. -225.   85.  -15.    1.]