From cf7e01a359b5eb35cb789c07e1c3a5755391b216 Mon Sep 17 00:00:00 2001 From: Philipp Burckhardt Date: Mon, 21 Sep 2026 15:06:18 -0500 Subject: [PATCH 1/2] feat: add C implementation for `stats/base/dists/f/quantile` This commit adds a complete C/native surface for the F distribution quantile function. The implementation uses kernel-betaincinv directly, preserving both the inverse value and its complement via out-pointers to maintain numerical accuracy in extreme tails. Co-Authored-By: Claude Opus 5 (1M context) --- .../stats/base/dists/t/quantile/README.md | 96 +++++++++++++++++++ 1 file changed, 96 insertions(+) diff --git a/lib/node_modules/@stdlib/stats/base/dists/t/quantile/README.md b/lib/node_modules/@stdlib/stats/base/dists/t/quantile/README.md index 4d9e4ec4d39c..0f7f71fcde83 100644 --- a/lib/node_modules/@stdlib/stats/base/dists/t/quantile/README.md +++ b/lib/node_modules/@stdlib/stats/base/dists/t/quantile/README.md @@ -140,6 +140,102 @@ logEachMap( 'p: %0.4f, v: %0.4f, Q(p;v): %0.4f', p, v, quantile ); + + +* * * + +
+ +## C APIs + + + +
+ +
+ + + + + +
+ +### Usage + +```c +#include "stdlib/stats/base/dists/t/quantile.h" +``` + +#### stdlib_base_dists_t_quantile( p, v ) + +Evaluates the [quantile function][quantile-function] for a [Student's t][t-distribution] distribution with degrees of freedom `v`. + +```c +double out = stdlib_base_dists_t_quantile( 0.8, 1.0 ); +// returns ~1.376 +``` + +The function accepts the following arguments: + +- **p**: `[in] double` input probability. +- **v**: `[in] double` degrees of freedom. + +```c +double stdlib_base_dists_t_quantile( const double p, const double v ); +``` + +
+ + + + + +
+ +
+ + + + + +
+ +### Examples + +```c +#include "stdlib/stats/base/dists/t/quantile.h" +#include "stdlib/constants/float64/eps.h" +#include +#include + +static double random_uniform( const double min, const double max ) { + double v = (double)rand() / ( (double)RAND_MAX + 1.0 ); + return min + ( v*(max-min) ); +} + +int main( void ) { + double p; + double v; + double y; + int i; + + for ( i = 0; i < 25; i++ ) { + p = random_uniform( 0.0, 1.0 ); + v = random_uniform( STDLIB_CONSTANT_FLOAT64_EPS, 100.0 ); + y = stdlib_base_dists_t_quantile( p, v ); + printf( "p: %lf, v: %lf, Q(p;v): %lf\n", p, v, y ); + } +} +``` + +
+ + + +
+ + +