Python script to compute Taylor expansion (cos(x)).

taylor_expansion_cos.py

#! /usr/local/bin/python3.6
"""
Taylor expansion (cos(x))
"""
import math
import sys
import traceback


class TaylorExpansionCos:
    EPS = 1e-08         # Precision
    PI  = 3.1415926535  # Pi

    def compute(self):
        """ Computation of Taylor expansion """
        try:
            rad = self.PI / 180
            print("    x      mycos(x)        cos(x)")
            for x in range(0, 181, 10):
                cos, cos_2 = math.cos(x * rad), self.__cos(x * rad)
                print("{:5.1f}{:14.6f}{:14.6f}".format(x, cos_2, cos))
        except Exception as e:
            raise

    def __cos(self, x):
        """ Computation of cos(x)

        :param  float   x
        :return float exp
        """
        try:
            d = s = e = 1.0
            x %=  2 * self.PI
            for k in range(1, 201, 2):
              d = s
              e *= -x * x / (k * (k + 1))
              s += e
              if abs(s - d) / abs(d) < self.EPS:
                  return s
            return 9999.0
        except Exception as e:
            raise


if __name__ == '__main__':
    try:
        obj = TaylorExpansionCos()
        obj.compute()
    except Exception as e:
        traceback.print_exc()
        sys.exit(1)