I am trying to use the Maclaurin series to estimate the sine of a number. This is my function:

from math import sin, factorial

import numpy as np

fac = np.vectorize(factorial)

def sin_x(x, terms=10):
    """ Calcul une approximation de sin(x) en utlisant
    un nombre donné de termes de la serie de Maclaurin"""
    
    n = np.arange(terms)
    return np.sum[((-1)**n)(x**(2*n 1)) / fac(2*n 1)]

if __name__ == "__main__":
    print("Valeur actuelle:", sin(5)) # En utilisant la fonction sinus de la librairie math
    
    print("N (terms)\tMaclaurin\tErreur")
    
    for n in range(1, 6):
        maclaurin = sin_x(5, terms=n)
        print(f"{n}\t\t{maclaurin:.03f}\t\t{sin(10) - maclaurin:.03f}")

and this is the error I get

PS C:\Users\tapef\Desktop\NUMPY-TUT> python maclaurin_sin.py
Valeur actuelle: -0.9589242746631385
N (terms)       Maclaurin       Erreur
Traceback (most recent call last):
  File "C:\Users\tapef\Desktop\NUMPY-TUT\maclaurin_sin.py", line 20, in <module>
    maclaurin = sin_x(5, terms=n)
  File "C:\Users\tapef\Desktop\NUMPY-TUT\maclaurin_sin.py", line 12, in sin_x
    return np.sum[((-1)**n)(x**(2*n 1)) / fac(2*n 1)]
TypeError: 'numpy.ndarray' object is not callable

How do I get rid of this error? Thanks

I've tried to use brackets instead of parenthetis.

CodePudding user response：

You forgot the multiplication between (-1)**n) and (x**(2*n 1). Furthermore, np.sum() needs to be called as a function, so your return statement becomes:

return np.sum(((-1)**n)*(x**(2*n 1)) / fac(2*n 1))