numpy.poly1d() in Python Last Updated : 09 Aug, 2022 Comments Improve Suggest changes Like Article Like Report The numpy.poly1d() function helps to define a polynomial function. It makes it easy to apply "natural operations" on polynomials. Syntax: numpy.poly1d(arr, root, var) Parameters : arr : [array_like] The polynomial coefficients are given in decreasing order of powers. If the second parameter (root) is set to True then array values are the roots of the polynomial equation. root : [bool, optional] True means polynomial roots. Default is False. var : variable like x, y, z that we need in polynomial [default is x]. Arguments : c : Polynomial coefficient. coef : Polynomial coefficient. coefficients : Polynomial coefficient. order : Order or degree of polynomial. o : Order or degree of polynomial. r : Polynomial root. roots : Polynomial root. Return: Polynomial and the operation applied For example: poly1d(3, 2, 6) = 3x2 + 2x + 6 poly1d([1, 2, 3], True) = (x-1)(x-2)(x-3) = x3 - 6x2 + 11x -6 Code 1 : Explaining poly1d() and its argument Python3 # Python code explaining # numpy.poly1d() # importing libraries import numpy as np # Constructing polynomial p1 = np.poly1d([1, 2]) p2 = np.poly1d([4, 9, 5, 4]) print ("P1 : ", p1) print ("\n p2 : \n", p2) # Solve for x = 2 print ("\n\np1 at x = 2 : ", p1(2)) print ("p2 at x = 2 : ", p2(2)) # Finding Roots print ("\n\nRoots of P1 : ", p1.r) print ("Roots of P2 : ", p2.r) # Finding Coefficients print ("\n\nCoefficients of P1 : ", p1.c) print ("Coefficients of P2 : ", p2.coeffs) # Finding Order print ("\n\nOrder / Degree of P1 : ", p1.o) print ("Order / Degree of P2 : ", p2.order) Output : P1 : 1 x + 2 p2 : 3 2 4 x + 9 x + 5 x + 4 p1 at x = 2 : 4 p2 at x = 2 : 82 Roots of P1 : [-2.] Roots of P2 : [-1.86738371+0.j -0.19130814+0.70633545j -0.19130814-0.70633545j] Coefficients of P1 : [1 2] Coefficients of P2 : [4 9 5 4] Order / Degree of P1 : 1 Order / Degree of P2 : 3 Code 2 : Basic mathematical operation on polynomial Python3 # Python code explaining # numpy.poly1d() # importing libraries import numpy as np # Constructing polynomial p1 = np.poly1d([1, 2]) p2 = np.poly1d([4, 9, 5, 4]) print ("P1 : ", p1) print ("\n p2 : \n", p2) print ("\n\np1 ^ 2 : \n", p1**2) print ("p2 ^ 2 : \n", np.square(p2)) p3 = np.poly1d([1, 2], variable = 'y') print ("\n\np3 : ", p3) print ("\n\np1 * p2 : \n", p1 * p2) print ("\nMultiplying two polynimials : \n", np.poly1d([1, -1]) * np.poly1d([1, -2])) Output : P1 : 1 x + 2 p2 : 3 2 4 x + 9 x + 5 x + 4 p1 ^ 2 : 2 1 x + 4 x + 4 p2 ^ 2 : [16 81 25 16] p3 : 1 y + 2 p1 * p2 : 4 3 2 4 x + 17 x + 23 x + 14 x + 8 Multiplying two polynomials : 2 1 x - 3 x + 2 Comment More infoAdvertise with us Next Article numpy.poly1d() in Python M mohit gupta_omg :) Follow Improve Article Tags : Python Python-numpy Python numpy-polynomials Practice Tags : python Similar Reads numpy.poly() in Python 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 t 2 min read numpy.polydiv() in Python The numpy.polydiv() method evaluates the division of two polynomials and returns the quotient and remainder of the polynomial division. Syntax : numpy.polydiv(p1, p2) Parameters : p1 : [array_like or poly1D]Coefficients of dividend polynomial. p2 : [array_like or poly1D]Coefficients of divisor polyn 1 min read numpy.polyder() in Python The numpy.polyder() method evaluates the derivative of a polynomial with specified order. Syntax :numpy.polyder(p, m) Parameters : p : [array_like or poly1D]the polynomial coefficients are given in decreasing order of powers. If the second parameter (root) is set to True then array values are the ro 2 min read numpy.polyadd() in Python numpy.polyadd() : This function helps to find the sum of two polynomials and then returning the result as a polynomial. Each input polynomial must be a sequence of polynomial coefficients, from highest to lowest degree. Parameters : p1 : Input polynomial 1 p2 : Input polynomial 2 Return : Sum of pol 1 min read numpy.polyval() in Python numpy.polyval(p, x) method evaluates a polynomial at specific values. If 'N' is the length of polynomial 'p', then this function returns the value Parameters : p : [array_like or poly1D] polynomial coefficients are given in decreasing order of powers. If the second parameter (root) is set to True th 2 min read Like