@stdlib/stats/incr/summary/README.md

Standard library statistical functions.

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# incrsummary

> Compute a statistical summary incrementally.

<section class="usage">

## Usage

```javascript
var incrsummary = require( '@stdlib/stats/incr/summary' );
```

#### incrsummary()

Returns an accumulator `function` which incrementally computes a statistical summary.

```javascript
var accumulator = incrsummary();
```

#### accumulator( \[x] )

If provided an input value `x`, the accumulator function returns an updated summary. If not provided an input value `x`, the accumulator function returns the current summary.

```javascript
var accumulator = incrsummary();

var summary = accumulator();
// returns {}

summary = accumulator( 2.0 );
/* returns
    {
        'count': 1,
        'max': 2.0,
        'min': 2.0,
        'range': 0.0,
        'midrange': 2.0,
        'sum': 2.0,
        'mean': 2.0,
        'variance': 0.0,
        'stdev': 0.0,
        'skewness': null,
        'kurtosis': null
    }
*/

summary = accumulator( 1.0 );
/* returns
    {
        'count': 2,
        'max': 2.0,
        'min': 1.0,
        'range': 1.0,
        'midrange': 1.5,
        'sum': 3.0,
        'mean': 1.5,
        'variance': 0.5,
        'stdev': 0.7071067811865476,
        'skewness': null,
        'kurtosis': null
    }
*/

summary = accumulator( -3.0 );
/* returns
    {
        'count': 3,
        'max': 2.0,
        'min': -3.0,
        'range': 5.0,
        'midrange': -0.5,
        'sum': 0.0,
        'mean': 0.0,
        'variance': 7,
        'stdev': ~2.65,
        'skewness': ~-1.46,
        'kurtosis': null
    }
*/

summary = accumulator();
/* returns
    {
        'count': 3,
        'max': 2.0,
        'min': -3.0,
        'range': 5.0,
        'midrange': -0.5,
        'sum': 0.0,
        'mean': 0.0,
        'variance': 7,
        'stdev': ~2.65,
        'skewness': ~-1.46,
        'kurtosis': null
    }
*/
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   Input values are **not** type checked. 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.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var randu = require( '@stdlib/random/base/randu' );
var incrsummary = require( '@stdlib/stats/incr/summary' );

var accumulator;
var v;
var i;

// Initialize an accumulator:
accumulator = incrsummary();

// For each simulated datum, update the summary...
for ( i = 0; i < 100; i++ ) {
    v = randu() * 100.0;
    accumulator( v );
}
console.log( accumulator() );
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/stats/incr/count`][@stdlib/stats/incr/count]</span><span class="delimiter">: </span><span class="description">compute a count incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/kurtosis`][@stdlib/stats/incr/kurtosis]</span><span class="delimiter">: </span><span class="description">compute a corrected sample excess kurtosis incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/max`][@stdlib/stats/incr/max]</span><span class="delimiter">: </span><span class="description">compute a maximum value incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/mean`][@stdlib/stats/incr/mean]</span><span class="delimiter">: </span><span class="description">compute an arithmetic mean incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/midrange`][@stdlib/stats/incr/midrange]</span><span class="delimiter">: </span><span class="description">compute a mid-range incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/min`][@stdlib/stats/incr/min]</span><span class="delimiter">: </span><span class="description">compute a minimum value incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/msummary`][@stdlib/stats/incr/msummary]</span><span class="delimiter">: </span><span class="description">compute a moving statistical summary incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/range`][@stdlib/stats/incr/range]</span><span class="delimiter">: </span><span class="description">compute a range incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/skewness`][@stdlib/stats/incr/skewness]</span><span class="delimiter">: </span><span class="description">compute a corrected sample skewness incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/stdev`][@stdlib/stats/incr/stdev]</span><span class="delimiter">: </span><span class="description">compute a corrected sample standard deviation incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/sum`][@stdlib/stats/incr/sum]</span><span class="delimiter">: </span><span class="description">compute a sum incrementally.</span>
-   <span class="package-name">[`@stdlib/stats/incr/variance`][@stdlib/stats/incr/variance]</span><span class="delimiter">: </span><span class="description">compute an unbiased sample variance incrementally.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

<!-- <related-links> -->

[@stdlib/stats/incr/count]: https://github.com/stdlib-js/stats/tree/main/incr/count

[@stdlib/stats/incr/kurtosis]: https://github.com/stdlib-js/stats/tree/main/incr/kurtosis

[@stdlib/stats/incr/max]: https://github.com/stdlib-js/stats/tree/main/incr/max

[@stdlib/stats/incr/mean]: https://github.com/stdlib-js/stats/tree/main/incr/mean

[@stdlib/stats/incr/midrange]: https://github.com/stdlib-js/stats/tree/main/incr/midrange

[@stdlib/stats/incr/min]: https://github.com/stdlib-js/stats/tree/main/incr/min

[@stdlib/stats/incr/msummary]: https://github.com/stdlib-js/stats/tree/main/incr/msummary

[@stdlib/stats/incr/range]: https://github.com/stdlib-js/stats/tree/main/incr/range

[@stdlib/stats/incr/skewness]: https://github.com/stdlib-js/stats/tree/main/incr/skewness

[@stdlib/stats/incr/stdev]: https://github.com/stdlib-js/stats/tree/main/incr/stdev

[@stdlib/stats/incr/sum]: https://github.com/stdlib-js/stats/tree/main/incr/sum

[@stdlib/stats/incr/variance]: https://github.com/stdlib-js/stats/tree/main/incr/variance

<!-- </related-links> -->

</section>

<!-- /.links -->