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27 lines
731 B
Python
27 lines
731 B
Python
10 years ago
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#!/usr/bin/python
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from __future__ import division, print_function
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from math import pow
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import random
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epsilon = 1e-09
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def derive(function, x):
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"""Poor man's numerical derivation."""
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return (function(x+epsilon)-function(x-epsilon))/(2*epsilon)
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def newton(function, x_0, max_i=50):
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"""Find a real root of a function using Newton's method."""
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x = x_0
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for i in range(max_i):
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x = x - (function(x)/derive(function, x))
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print('f({}) = {}'.format(x, function(x)))
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if abs(function(x)) < epsilon:
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return x
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break
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else:
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return x
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print(newton(lambda x: x**4 + 3*x - 1, x_0=100*random.random()))
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#print(newton(lambda x: pow(x, 0.333), x_0=100*random.random()))
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