Functions - Orbifold/XAct GitHub Wiki

Contains a variety of mathematical functions and utilities related to (real) functions.

Fibonacci

Returns the n-th Fibonacci number. The first 100 are cached and performance thereafter degrades rapidly as the value is recursively calculated. The 130-th value takes around 5secs.

BetaRegularized

Returns the regularized lower incomplete beta function. The regularized incomplete beta function (or regularized beta function for short) is defined in terms of the incomplete beta function and the complete beta function.