npm package: @stdlib/blas-ext-base-ndarray-gcusumkbn
Description: Compute the cumulative sum of a one-dimensional ndarray using an improved Kahan–Babuška algorithm.
Author: The Stdlib Authors
Latest version: 0.1.1

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# gcusumkbn

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> Compute the cumulative sum of a one-dimensional ndarray using an improved Kahan–Babuška algorithm.

<section class="intro">

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/blas-ext-base-ndarray-gcusumkbn
```

</section>

<section class="usage">

## Usage

```javascript
var gcusumkbn = require( '@stdlib/blas-ext-base-ndarray-gcusumkbn' );
```

#### gcusumkbn( arrays )

Computes the cumulative sum of a one-dimensional ndarray using an improved Kahan–Babuška algorithm.

```javascript
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var scalar2ndarray = require( '@stdlib/ndarray-base-from-scalar' );
var ndarray = require( '@stdlib/ndarray-base-ctor' );

var xbuf = [ 1.0, 3.0, 4.0, 2.0 ];
var x = new ndarray( 'generic', xbuf, [ 4 ], [ 1 ], 0, 'row-major' );

var ybuf = [ 0.0, 0.0, 0.0, 0.0 ];
var y = new ndarray( 'generic', ybuf, [ 4 ], [ 1 ], 0, 'row-major' );

var initial = scalar2ndarray( 0.0, 'generic', 'row-major' );

var v = gcusumkbn( [ x, y, initial ] );
// returns <ndarray>

var bool = ( v === y );
// returns true

var arr = ndarray2array( v );
// returns [ 1.0, 4.0, 8.0, 10.0 ]
```

The function has the following parameters:

-   **arrays**: array-like object containing a one-dimensional input ndarray, a one-dimensional output ndarray, and a zero-dimensional ndarray containing the initial sum.

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   If provided an empty one-dimensional input ndarray, the function returns the output ndarray unchanged.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var ndarray = require( '@stdlib/ndarray-base-ctor' );
var zerosLike = require( '@stdlib/ndarray-zeros-like' );
var scalar2ndarray = require( '@stdlib/ndarray-from-scalar' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var gcusumkbn = require( '@stdlib/blas-ext-base-ndarray-gcusumkbn' );

var xbuf = discreteUniform( 10, -50, 50, {
    'dtype': 'generic'
});
var x = new ndarray( 'generic', xbuf, [ xbuf.length ], [ 1 ], 0, 'row-major' );
console.log( ndarray2array( x ) );

var y = zerosLike( x );
console.log( ndarray2array( y ) );

var initial = scalar2ndarray( 100.0, {
    'dtype': 'generic'
});

var v = gcusumkbn( [ x, y, initial ] );
console.log( ndarray2array( v ) );
```

</section>

<!-- /.examples -->

<section class="references">

## References

-   Neumaier, Arnold. 1974. "Rounding Error Analysis of Some Methods for Summing Finite Sums." _Zeitschrift Für Angewandte Mathematik Und Mechanik_ 54 (1): 39–51. doi:[10.1002/zamm.19740540106][@neumaier:1974a].

</section>

<!-- /.references -->

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</section>

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* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

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---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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[@neumaier:1974a]: https://doi.org/10.1002/zamm.19740540106

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