@stdlib/stats/base/dists/degenerate/logpmf/README.md

Standard library statistical functions.

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# Logarithm of Probability Mass Function

> Evaluate the natural logarithm of the [probability mass function][pmf] (PMF) for a [degenerate distribution][degenerate-distribution].

<section class="intro">

</section>

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<section class="usage">

## Usage

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

#### logpmf( x, mu )

Evaluates the natural logarithm of the [PMF][pmf] for a [degenerate distribution][degenerate-distribution] centered at `mu`.

```javascript
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][pmf] of a [degenerate distribution][degenerate-distribution] centered at `mu`.

```javascript
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
```

</section>

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<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
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 );
}
```

</section>

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<section class="links">

[pmf]: https://en.wikipedia.org/wiki/Probability_mass_function

[degenerate-distribution]: https://en.wikipedia.org/wiki/Degenerate_distribution

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