Median

Arcsine distribution median.

The median for an arcsine random variable is

$$\mathrm{Median}\left(X\right)=\frac{1}{2}\cdot (a+b)$$

where a is the minimum support and b is the maximum support.

Usage

var median = require( '@stdlib/stats/base/dists/arcsine/median' );

median( a, b )

Returns the median of an arcsine distribution with parameters a (minimum support) and b (maximum support).

var v = median( 0.0, 1.0 );
// returns 0.5

v = median( 4.0, 12.0 );
// returns 8.0

v = median( 2.0, 8.0 );
// returns 5.0

If provided NaN as any argument, the function returns NaN.

var v = median( NaN, 2.0 );
// returns NaN

v = median( 2.0, NaN );
// returns NaN

If provided a >= b, the function returns NaN.

var y = median( 3.0, 2.0 );
// returns NaN

y = median( 3.0, 3.0 );
// returns NaN

Examples

var uniform = require( '@stdlib/random/array/uniform' );
var logEachMap = require( '@stdlib/console/log-each-map' );
var median = require( '@stdlib/stats/base/dists/arcsine/median' );

var opts = {
    'dtype': 'float64'
};
var a = uniform( 25, 0.0, 10.0, opts );
var b = uniform( a.length, 10.0, 20.0, opts );

logEachMap( 'a: %0.4f, b: %0.4f, Median(X;a,b): %0.4f', a, b, median );

---

C APIs

Usage

#include "stdlib/stats/base/dists/arcsine/median.h"

stdlib_base_dists_arcsine_median( a, b )

Returns the median of an arcsine distribution.

double out = stdlib_base_dists_arcsine_median( 0.0, 1.0 );
// returns 0.5

The function accepts the following arguments:

• a: [in] double minimum support.
• b: [in] double maximum support.

double stdlib_base_dists_arcsine_median( const double a, const double b );

Examples

#include "stdlib/stats/base/dists/arcsine/median.h"
#include <stdlib.h>
#include <stdio.h>

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 a;
    double b;
    double y;
    int i;

    for ( i = 0; i < 10; i++ ) {
        a = random_uniform( 0.0, 10.0 );
        b = random_uniform( a, a+10.0 );
        y = stdlib_base_dists_arcsine_median( a, b );
        printf( "a: %lf, b: %lf, Median(X;a,b): %lf\n", a, b, y );
    }
}