# incrsumabs2
> Compute a sum of squared absolute values incrementally.
The sum of squared absolute values is defined as
## Usage
```javascript
var incrsumabs2 = require( '@stdlib/stats/incr/sumabs2' );
```
#### incrsumabs2()
Returns an accumulator `function` which incrementally computes a sum of squared absolute values.
```javascript
var accumulator = incrsumabs2();
```
#### accumulator( \[x] )
If provided an input value `x`, the accumulator function returns an updated sum. If not provided an input value `x`, the accumulator function returns the current sum.
```javascript
var accumulator = incrsumabs2();
var sum = accumulator( 2.0 );
// returns 4.0
sum = accumulator( -1.0 );
// returns 5.0
sum = accumulator( -3.0 );
// returns 14.0
sum = accumulator();
// returns 14.0
```
## Notes
- Input values are **not** type checked. If provided `NaN` or a value which, when used in computations, results in `NaN`, the accumulated value is `NaN` for **all** future invocations. If non-numeric inputs are possible, you are advised to type check and handle accordingly **before** passing the value to the accumulator function.
- For long running accumulations or accumulations of large numbers, care should be taken to prevent overflow.
## Examples
```javascript
var randu = require( '@stdlib/random/base/randu' );
var incrsumabs2 = require( '@stdlib/stats/incr/sumabs2' );
var accumulator;
var v;
var i;
// Initialize an accumulator:
accumulator = incrsumabs2();
// For each simulated datum, update the sum...
for ( i = 0; i < 100; i++ ) {
v = ( randu()*100.0 ) - 50.0;
accumulator( v );
}
console.log( accumulator() );
```
