Python/maths/numerical_analysis/intersection.py
Tianyi Zheng a8b6bda993
Delete arithmetic_analysis/ directory and relocate its contents (#10824)
* Remove eval from arithmetic_analysis/newton_raphson.py

* Relocate contents of arithmetic_analysis/

Delete the arithmetic_analysis/ directory and relocate its files because
the purpose of the directory was always ill-defined. "Arithmetic
analysis" isn't a field of math, and the directory's files contained
algorithms for linear algebra, numerical analysis, and physics.

Relocated the directory's linear algebra algorithms to linear_algebra/,
its numerical analysis algorithms to a new subdirectory called
maths/numerical_analysis/, and its single physics algorithm to physics/.

* updating DIRECTORY.md

---------

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
2023-10-23 09:31:30 +02:00

50 lines
1.5 KiB
Python

import math
from collections.abc import Callable
def intersection(function: Callable[[float], float], x0: float, x1: float) -> float:
"""
function is the f we want to find its root
x0 and x1 are two random starting points
>>> intersection(lambda x: x ** 3 - 1, -5, 5)
0.9999999999954654
>>> intersection(lambda x: x ** 3 - 1, 5, 5)
Traceback (most recent call last):
...
ZeroDivisionError: float division by zero, could not find root
>>> intersection(lambda x: x ** 3 - 1, 100, 200)
1.0000000000003888
>>> intersection(lambda x: x ** 2 - 4 * x + 3, 0, 2)
0.9999999998088019
>>> intersection(lambda x: x ** 2 - 4 * x + 3, 2, 4)
2.9999999998088023
>>> intersection(lambda x: x ** 2 - 4 * x + 3, 4, 1000)
3.0000000001786042
>>> intersection(math.sin, -math.pi, math.pi)
0.0
>>> intersection(math.cos, -math.pi, math.pi)
Traceback (most recent call last):
...
ZeroDivisionError: float division by zero, could not find root
"""
x_n: float = x0
x_n1: float = x1
while True:
if x_n == x_n1 or function(x_n1) == function(x_n):
raise ZeroDivisionError("float division by zero, could not find root")
x_n2: float = x_n1 - (
function(x_n1) / ((function(x_n1) - function(x_n)) / (x_n1 - x_n))
)
if abs(x_n2 - x_n1) < 10**-5:
return x_n2
x_n = x_n1
x_n1 = x_n2
def f(x: float) -> float:
return math.pow(x, 3) - (2 * x) - 5
if __name__ == "__main__":
print(intersection(f, 3, 3.5))