Python script to compute nonlinear equation with Newton method.

nonlinear_equation_newton.py

#! /usr/local/bin/python3.6
"""
Nonlinear equation with Newton method
"""
import sys
import traceback


class NonlinearEquationNewton:
    EPS = 1e-08  # Precision of truncation
    LIMIT = 50   # Number of truncation

    def __init__(self):
        self.f = lambda x: x**3 - x + 1
        self.g = lambda x: 3 * x**2 - 1

    def compute(self):
        """
        Computation of nonlinear equation with bisection method
        """
        try:
            x = -2.0
            cnt_loop = 0
            for k in range(1, self.LIMIT + 1):
                cnt_loop = k
                dx = x
                x -= self.f(x) / self.g(x)
                if abs(x - dx) / abs(dx) < self.EPS:
                    print("x = {:f}".format(x))
                    break
            if cnt_loop == self.LIMIT:
                print("収束しない")
        except Exception as e:
            raise


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