numpy.poly() in Python (original) (raw)

Last Updated : 04 Dec, 2020

The numpy.poly() function in the Sequence of roots of the polynomial returns the coefficient of the polynomial.

**Syntax :**numpy.poly(seq)

Parameters :
Seq : sequence of roots of the polynomial roots, or a matrix of roots.

Return: 1D array having coefficients of the polynomial from the highest degree to the lowest one.
c[0] * x**(N) + c[1] * x**(N-1) + … + c[N-1] * x + c[N] where c[0] always equals 1.

import numpy as np

seq_1 = ( 2 , 1 , 0 )

a = np.poly(seq_1)

print ( "Coefficients of the polynomial: " , a)

p1 = np.poly1d(a)

print ( "\nAbove polynomial = \n" , p1)

Output :

Coefficients of the polynomial: [ 1. -3. 2. 0.]

Above polynomial = 3 2 1 x - 3 x + 2 x

Code #2:

import numpy as np

seq_2 = ( 2 , 1 , 0 , 2 , 4 , 2 )

b = np.poly(seq_2)

print ( "Coefficients of the polynomial: " , b)

p2 = np.poly1d(b)

print ( "\nAbove polynomial = \n" , p2)

Output :

Coefficients of the polynomial: [ 1. -11. 46. -92. 88. -32. 0.]

Above polynomial = 6 5 4 3 2 1 x - 11 x + 46 x - 92 x + 88 x - 32 x

Similar Reads