# itercumean
> Create an [iterator][mdn-iterator-protocol] which iteratively computes a cumulative [arithmetic mean][arithmetic-mean].
The cumulative [arithmetic mean][arithmetic-mean] is defined as
## Usage
```javascript
var itercumean = require( '@stdlib/stats/iter/cumean' );
```
#### itercumean( iterator )
Returns an [iterator][mdn-iterator-protocol] which iteratively computes a cumulative [arithmetic mean][arithmetic-mean].
```javascript
var array2iterator = require( '@stdlib/array/to-iterator' );
var arr = array2iterator( [ 2.0, 1.0, 3.0, -7.0, -5.0 ] );
var it = itercumean( arr );
var m = it.next().value;
// returns 2.0
m = it.next().value;
// returns 1.5
m = it.next().value;
// returns 2.0
m = it.next().value;
// returns -0.25
m = it.next().value;
// returns -1.2
```
## Notes
- If an iterated value is non-numeric (including `NaN`), the function returns `NaN` for **all** future iterations. If non-numeric iterated values are possible, you are advised to provide an [`iterator`][mdn-iterator-protocol] which type checks and handles non-numeric values accordingly.
## Examples
```javascript
var runif = require( '@stdlib/random/iter/uniform' );
var itercumean = require( '@stdlib/stats/iter/cumean' );
// Create an iterator for generating uniformly distributed pseudorandom numbers:
var rand = runif( -10.0, 10.0, {
'seed': 1234,
'iter': 100
});
// Create an iterator for iteratively computing a cumulative mean:
var it = itercumean( rand );
// Perform manual iteration...
var v;
while ( true ) {
v = it.next();
if ( typeof v.value === 'number' ) {
console.log( 'mean: %d', v.value );
}
if ( v.done ) {
break;
}
}
```
[arithmetic-mean]: https://en.wikipedia.org/wiki/Arithmetic_mean
[mdn-iterator-protocol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol
