maths.fast_inverse_sqrt

Fast inverse square root (1/sqrt(x)) using the Quake III algorithm. Reference: https://en.wikipedia.org/wiki/Fast_inverse_square_root Accuracy: https://en.wikipedia.org/wiki/Fast_inverse_square_root#Accuracy

Functions

fast_inverse_sqrt(→ float)

Compute the fast inverse square root of a floating-point number using the famous

Module Contents

maths.fast_inverse_sqrt.fast_inverse_sqrt(number: float) → float

Compute the fast inverse square root of a floating-point number using the famous Quake III algorithm.

Parameters:

number (float) – Input number for which to calculate the inverse square root.

Return float:

The fast inverse square root of the input number.

Example: >>> fast_inverse_sqrt(10) 0.3156857923527257 >>> fast_inverse_sqrt(4) 0.49915357479239103 >>> fast_inverse_sqrt(4.1) 0.4932849504615651 >>> fast_inverse_sqrt(0) Traceback (most recent call last):

…

ValueError: Input must be a positive number. >>> fast_inverse_sqrt(-1) Traceback (most recent call last):

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ValueError: Input must be a positive number. >>> from math import isclose, sqrt >>> all(isclose(fast_inverse_sqrt(i), 1 / sqrt(i), rel_tol=0.00132) … for i in range(50, 60)) True