Python中的 numpy.polymul()

numpy.polymul()方法计算两个多项式的乘积，并返回由两个输入多项式“p1”和“p2”相乘得到的多项式。

Syntax : numpy.polymul(p1, p2)
Parameters :
p1 : [array_like or poly1D]Input polynomial 1.
p2 : [array_like or poly1D]Input polynomial 2.

Return: Polynomial resulting from multiplication of the inputs.

如果任一输入是poly1D对象，则输出也是 poly1D 对象，否则为多项式系数的 1D 数组，按度数降序排列。

代码：解释 polymul() 的Python代码

# Python code explaining 
# numpy.polymul()
    
# importing libraries
import numpy as np
import pandas as pd
  
# Constructing polynomial 
p1 = np.poly1d([1, 2]) 
p2 = np.poly1d([4, 9, 5, 4]) 
    
print ("P1 : ", p1) 
print ("\n p2 : \n", p2) 

mul = np.polymul(p2, p1)
  
print("\n\npoly1D object : ")
print("Multiplication Result  : \n", mul)

# Defining ndarray
x = np.array([1, 2])
y = np.array([4, 9, 5, 4])
mul = np.polymul(y, x)
  
print("\n1D array : ")
print("Multiplication Result  : ", mul)