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# dnansumkbn2

> Compute the sum of a one-dimensional double-precision floating-point ndarray, ignoring `NaN` values and using a second-order iterative Kahan–Babuška algorithm.

<section class="intro">

</section>

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<section class="usage">

## Usage

```javascript
var dnansumkbn2 = require( '@stdlib/blas/ext/base/ndarray/dnansumkbn2' );
```

#### dnansumkbn2( arrays )

Computes the sum of a one-dimensional double-precision floating-point ndarray, ignoring `NaN` values and using a second-order iterative Kahan–Babuška algorithm.

```javascript
var Float64Vector = require( '@stdlib/ndarray/vector/float64' );

var x = new Float64Vector( [ 1.0, -2.0, NaN, 2.0 ] );

var v = dnansumkbn2( [ x ] );
// returns 1.0
```

The function has the following parameters:

-   **arrays**: array-like object containing a one-dimensional input ndarray.

</section>

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<section class="notes">

## Notes

-   If provided an empty one-dimensional ndarray, the function returns `0.0`.

</section>

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<section class="examples">

## Examples

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

```javascript
var bernoulli = require( '@stdlib/random/base/bernoulli' );
var discreteUniform = require( '@stdlib/random/base/discrete-uniform' );
var fillBy = require( '@stdlib/ndarray/fill-by' );
var zeros = require( '@stdlib/ndarray/zeros' );
var ndarray2array = require( '@stdlib/ndarray/to-array' );
var dnansumkbn2 = require( '@stdlib/blas/ext/base/ndarray/dnansumkbn2' );

function clbk() {
    if ( bernoulli( 0.7 ) > 0 ) {
        return discreteUniform( 0, 100 );
    }
    return NaN;
}

var opts = {
    'dtype': 'float64'
};
var x = fillBy( zeros( [ 10 ], opts ), clbk );
console.log( ndarray2array( x ) );

var v = dnansumkbn2( [ x ] );
console.log( 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>

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<section class="related">

</section>

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<section class="links">

[@klein:2005a]: https://doi.org/10.1007/s00607-005-0139-x

</section>

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