Wilcoxon signed rank test statistic probability density function (PDF).
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> Wilcoxon signed rank test statistic [probability density function][pdf].
``bash`
npm install @stdlib/stats-base-dists-signrank-pdf
`javascript`
var pdf = require( '@stdlib/stats-base-dists-signrank-pdf' );
#### pdf( x, n )
Evaluates the [probability density function][pdf] of the Wilcoxon signed rank test statistic with n observations.
`javascript
var y = pdf( 7.0, 9 );
// returns ~0.0098
y = pdf( 7.0, 6 );
// returns ~0.063
y = pdf( -1.0, 40 );
// returns 0.0
`
If provided NaN as any argument, the function returns NaN.
`javascript
var y = pdf( NaN, 8 );
// returns NaN
y = pdf( 0.0, NaN );
// returns NaN
`
If provided x < 0, the function returns NaN.
`javascript`
var y = pdf( 2.0, -1.0 );
// returns NaN
If not provided a positive integer for n, the function returns NaN.
`javascript
var y = pdf( 2.0, 0 );
// returns NaN
y = pdf( 2.0, -2 );
// returns NaN
y = pdf( 2.0, 8.9 );
// returns NaN
`
#### pdf.factory( n )
Returns a function for evaluating the [probability density function][pdf] of the Wilcoxon signed rank test statistic with n observations.
`javascript
var mypdf = pdf.factory( 8 );
var y = mypdf( 4.0 );
// returns ~0.008
y = mypdf( 17.0 );
// returns ~0.051
`
`javascript
var ceil = require( '@stdlib/math-base-special-ceil' );
var randu = require( '@stdlib/random-base-randu' );
var pdf = require( '@stdlib/stats-base-dists-signrank-pdf' );
var n;
var x;
var y;
var i;
for ( i = 0; i < 10; i++ ) {
x = randu() * 30.0;
n = ceil( randu() * 30.0 );
y = pdf( x, n );
console.log( 'x: %d, n: %d, f(x;n): %d', x.toFixed( 4 ), n.toFixed( 4 ), y.toFixed( 4 ) );
}
`
*
`c`
#include "stdlib/stats/base/dists/signrank/pdf.h"
#### stdlib_base_dists_signrank_pdf( x, n )
Evaluates the probability density function (PDF) of the Wilcoxon signed rank test statistic with n observations.
`c`
double out = stdlib_base_dists_signrank_pdf( 7.0, 9 );
// returns ~0.01
The function accepts the following arguments:
- x: [in] double input value.[in] int32_t
- n: number of observations.
`c`
double stdlib_base_dists_signrank_pdf( const double x, const int32_t n );
`c
#include "stdlib/stats/base/dists/signrank/pdf.h"
#include "stdlib/math/base/special/ceil.h"
#include
#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 ) {
int32_t n;
double x;
double y;
int i;
for ( i = 0; i < 25; i++ ) {
x = random_uniform( 0, 30.0 );
n = (int32_t)stdlib_base_ceil( random_uniform( 1.0, 30.0 ) );
y = stdlib_base_dists_signrank_pdf( x, n );
printf( "x: %lf, n: %d, f(x;n): %lf\n", x, n, y );
}
}
`
*
This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
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Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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