@stdlib/stats-base-dists-triangular-entropy

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Entropy

Triangular distribution differential entropy.

The differential entropy (in nats) for a triangular random variable with lower limit a, upper limit b, and mode c is

Installation

npm install @stdlib/stats-base-dists-triangular-entropy

Usage

var entropy = require( '@stdlib/stats-base-dists-triangular-entropy' );

entropy( a, b, c )

Returns the differential entropy of a triangular distribution with minimum support a, maximum supportb, and mode c (in nats).

var v = entropy( 0.0, 1.0, 0.8 );
// returns ~-0.193

v = entropy( 4.0, 12.0, 5.0 );
// returns ~1.886

v = entropy( 2.0, 8.0, 5.0 );
// returns ~1.599

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

var v = entropy( NaN, 4.0, 2.0 );
// returns NaN

v = entropy( 0.0, NaN, 2.0 );
// returns NaN

v = entropy( 0.0, 4.0, NaN );
// returns NaN

If provided parameters not satisfying a <= c <= b, the function returns NaN.

var y = entropy( 1.0, 0.0, 1.5 );
// returns NaN

y = entropy( 0.0, 1.0, -1.0 );
// returns NaN

y = entropy( 0.0, -1.0, 0.5 );
// returns NaN

Examples

var randu = require( '@stdlib/random-base-randu' );
var entropy = require( '@stdlib/stats-base-dists-triangular-entropy' );

var a;
var b;
var c;
var v;
var i;

for ( i = 0; i < 10; i++ ) {
    a = ( randu()*10.0 );
    b = ( randu()*10.0 ) + a;
    c = ( randu()*( b-a ) ) + a;
    v = entropy( a, b, c );
    console.log( 'a: %d, b: %d, c: %d, h(X;a,b,c): %d', a.toFixed( 4 ), b.toFixed( 4 ), c.toFixed( 4 ), v.toFixed( 4 ) );
}

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C APIs

Usage

#include "stdlib/stats/base/dists/triangular/entropy.h"

stdlib_base_dists_triangular_entropy( a, b, c )

Returns the differential entropy of a triangular distribution with minimum support a, maximum supportb, and mode c (in nats).

double out = stdlib_base_dists_triangular_entropy( 0.0, 1.0, 0.5 );
// returns ~-0.193

The function accepts the following arguments:

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

double stdlib_base_dists_triangular_entropy( const double a, const double b, const double c );

Examples

#include "stdlib/stats/base/dists/triangular/entropy.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 c;
    double v;
    int i;

    for ( i = 0; i < 25; i++ ) {
        a = random_uniform( 0.0, 10.0 );
        b = random_uniform( a, a+10.0 );
        c = random_uniform( a, b );
        v = stdlib_base_dists_triangular_entropy( a, b, c );
        printf( "a: %lf, b: %lf, c: %lf, h(X;a,b,c): %lf\n", a, b, c, v );
    }
}

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Notice

This package is part of 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, see the main project repository.

Community

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License

See LICENSE.

Copyright

Copyright 2016-2026. The Stdlib Authors.