npm package: @stdlib/blas-ext-base-ndarray-dcusumkbn2
Description: Compute the cumulative sum of a one-dimensional double-precision floating-point ndarray using a second-order iterative Kahan–Babuška algorithm.
Author: The Stdlib Authors
Latest version: 0.1.1

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# dcusumkbn2

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> Compute the cumulative sum of a one-dimensional double-precision floating-point ndarray using a second-order iterative Kahan–Babuška algorithm.

<section class="intro">

</section>

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<section class="installation">

## Installation

```bash
npm install @stdlib/blas-ext-base-ndarray-dcusumkbn2
```

</section>

<section class="usage">

## Usage

```javascript
var dcusumkbn2 = require( '@stdlib/blas-ext-base-ndarray-dcusumkbn2' );
```

#### dcusumkbn2( arrays )

Computes the cumulative sum of a one-dimensional double-precision floating-point ndarray using a second-order iterative Kahan–Babuška algorithm.

```javascript
var Float64Array = require( '@stdlib/array-float64' );
var scalar2ndarray = require( '@stdlib/ndarray-base-from-scalar' );
var ndarray = require( '@stdlib/ndarray-base-ctor' );

var xbuf = new Float64Array( [ 1.0, 3.0, 4.0, 2.0 ] );
var x = new ndarray( 'float64', xbuf, [ 4 ], [ 1 ], 0, 'row-major' );

var ybuf = new Float64Array( [ 0.0, 0.0, 0.0, 0.0 ] );
var y = new ndarray( 'float64', ybuf, [ 4 ], [ 1 ], 0, 'row-major' );

var initial = scalar2ndarray( 0.0, 'float64', 'row-major' );

var v = dcusumkbn2( [ x, y, initial ] );
// returns <ndarray>[ 1.0, 4.0, 8.0, 10.0 ]

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

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 dcusumkbn2 = require( '@stdlib/blas-ext-base-ndarray-dcusumkbn2' );

var xbuf = discreteUniform( 10, -50, 50, {
    'dtype': 'float64'
});
var x = new ndarray( 'float64', 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': 'float64'
});

var v = dcusumkbn2( [ x, y, initial ] );
console.log( ndarray2array( v ) );
```

</section>

<!-- /.examples -->

<section class="references">

## References

-   Klein, Andreas. 2005. "A Generalized Kahan-Babuška-Summation-Algorithm." _Computing_ 76 (3): 279–93. doi:[10.1007/s00607-005-0139-x][@klein:2005a].

</section>

<!-- /.references -->

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* * *

## Notice

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## License

See [LICENSE][stdlib-license].


## Copyright

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

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