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34 lines
1.0 KiB
Python
34 lines
1.0 KiB
Python
# Implementing Newton Raphson method in Python
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# Author: Syed Haseeb Shah (github.com/QuantumNovice)
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#The Newton-Raphson method (also known as Newton's method) is a way to
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#quickly find a good approximation for the root of a real-valued function
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from sympy import diff
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from decimal import Decimal
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def NewtonRaphson(func, a):
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''' Finds root from the point 'a' onwards by Newton-Raphson method '''
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while True:
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c = Decimal(a) - ( Decimal(eval(func)) / Decimal(eval(str(diff(func)))) )
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a = c
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# This number dictates the accuracy of the answer
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if abs(eval(func)) < 10**-15:
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return c
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# Let's Execute
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if __name__ == '__main__':
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# Find root of trigonometric function
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# Find value of pi
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print('sin(x) = 0', NewtonRaphson('sin(x)', 2))
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# Find root of polynomial
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print('x**2 - 5*x +2 = 0', NewtonRaphson('x**2 - 5*x +2', 0.4))
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# Find Square Root of 5
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print('x**2 - 5 = 0', NewtonRaphson('x**2 - 5', 0.1))
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# Exponential Roots
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print('exp(x) - 1 = 0', NewtonRaphson('exp(x) - 1', 0))
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