## Usage
```javascript
var poisson = require( '@stdlib/stats/base/dists/poisson' );
```
#### poisson
Poisson distribution.
```javascript
var dist = poisson;
// returns {...}
```
The namespace contains the following distribution functions:
- [`cdf( x, lambda )`][@stdlib/stats/base/dists/poisson/cdf]: Poisson distribution cumulative distribution function.
- [`logpmf( x, lambda )`][@stdlib/stats/base/dists/poisson/logpmf]: evaluate the natural logarithm of the probability mass function (PMF) for a Poisson distribution.
- [`mgf( t, lambda )`][@stdlib/stats/base/dists/poisson/mgf]: Poisson distribution moment-generating function (MGF).
- [`pmf( x, lambda )`][@stdlib/stats/base/dists/poisson/pmf]: Poisson distribution probability mass function (PMF).
- [`quantile( p, lambda )`][@stdlib/stats/base/dists/poisson/quantile]: Poisson distribution quantile function.
The namespace contains the following functions for calculating distribution properties:
- [`kurtosis( lambda )`][@stdlib/stats/base/dists/poisson/kurtosis]: Poisson distribution excess kurtosis.
- [`mean( lambda )`][@stdlib/stats/base/dists/poisson/mean]: Poisson distribution expected value.
- [`median( lambda )`][@stdlib/stats/base/dists/poisson/median]: Poisson distribution median.
- [`mode( lambda )`][@stdlib/stats/base/dists/poisson/mode]: Poisson distribution mode.
- [`skewness( lambda )`][@stdlib/stats/base/dists/poisson/skewness]: Poisson distribution skewness.
- [`stdev( lambda )`][@stdlib/stats/base/dists/poisson/stdev]: Poisson distribution standard deviation.
- [`variance( lambda )`][@stdlib/stats/base/dists/poisson/variance]: Poisson distribution variance.
The namespace contains a constructor function for creating a [Poisson][poisson-distribution] distribution object.
- [`Poisson( [lambda] )`][@stdlib/stats/base/dists/poisson/ctor]: Poisson distribution constructor.
```javascript
var Poisson = require( '@stdlib/stats/base/dists/poisson' ).Poisson;
var dist = new Poisson( 2.0 );
var y = dist.pmf( 3.0 );
// returns ~0.18
y = dist.pmf( 2.3 );
// returns 0.0
```