Logarithm of Probability Mass Function

Evaluate the natural logarithm of the probability mass function (PMF) for a degenerate distribution.

Usage

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

logpmf( x, mu )

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

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

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

logpmf.factory( mu )

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

var mylogpmf = logpmf.factory( 10.0 );

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

y = mylogpmf( 5.0 );
// returns -Infinity

y = mylogpmf( 12.0 );
// returns -Infinity

Examples

var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );
var logpmf = require( '@stdlib/stats/base/dists/degenerate/logpmf' );

var mu;
var x;
var y;
var i;

for ( i = 0; i < 100; i++ ) {
    x = round( randu()*5.0 );
    mu = round( randu()*5.0 );
    y = logpmf( x, mu );
    console.log( 'x: %d, µ: %d, ln(P(X=x;µ)): %d', x, mu, y );
}