@stdlib/stats-base-dists-degenerate-logcdf

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Logarithm of Cumulative Distribution Function

Degenerate distribution logarithm of cumulative distribution function.

The cumulative distribution function for a degenerate random variable is

where µ is the constant value of the distribution.

Installation

npm install @stdlib/stats-base-dists-degenerate-logcdf

Usage

var logcdf = require( '@stdlib/stats-base-dists-degenerate-logcdf' );

logcdf( x, mu )

Evaluates the natural logarithm of the CDF of a degenerate distribution centered at mu.

var y = logcdf( 2.0, 8.0 );
// returns -Infinity

y = logcdf( 8.0, 8.0 );
// returns 0.0

y = logcdf( 10.0, 8.0 );
// returns 0.0

logcdf.factory( mu )

Returns a function for evaluating the natural logarithm of the cumulative distribution function of a degenerate distribution centered at mu.

var mylogcdf = logcdf.factory( 10.0 );

var y = mylogcdf( 10.0 );
// returns 0.0

y = mylogcdf( 8.0 );
// returns -Infinity

Examples

var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var logcdf = require( '@stdlib/stats-base-dists-degenerate-logcdf' );

var opts = {
    'dtype': 'float64'
};
var x = discreteUniform( 10, 0, 10, opts );
var mu = discreteUniform( 10, 0, 10, opts );

logEachMap( 'x: %d, µ: %d, ln(F(x;µ)): %0.4f', x, mu, logcdf );

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C APIs

Usage

#include "stdlib/stats/base/dists/degenerate/logcdf.h"

stdlib_base_dists_degenerate_logcdf( x, mu )

Evaluates the natural logarithm of the CDF of a degenerate distribution centered at mu.

double y = stdlib_base_dists_degenerate_logcdf( 2.0, 3.0 );
// returns -Infinity

The function accepts the following arguments:

• x: [in] double input value.
• mu: [in] double constant value of distribution.

double stdlib_base_dists_degenerate_logcdf( const double x, const double mu );

Examples

#include "stdlib/stats/base/dists/degenerate/logcdf.h"
#include "stdlib/math/base/special/round.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 mu;
    double x;
    double y;
    int i;

    for ( i = 0; i < 10; i++ ) {
        x = stdlib_base_round( random_uniform( 0.0, 10.0 ) );
        mu = stdlib_base_round( random_uniform( 0.0, 10.0 ) );
        y = stdlib_base_dists_degenerate_logcdf( x, mu );
        printf( "x: %lf, µ: %lf, ln(F(x;µ)): %lf\n", x, mu, y );
    }
}

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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.