npm package: @stdlib/stats-array-nanmskmax
Description: Calculate the maximum value of an array according to a mask, ignoring NaN values.
Author: The Stdlib Authors
Latest version: 0.1.1

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  <summary>
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# nanmskmax

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Calculate the maximum value of an array according to a mask, ignoring `NaN` values.

<section class="intro">

</section>

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<section class="installation">

## Installation

```bash
npm install @stdlib/stats-array-nanmskmax
```

</section>

<section class="usage">

## Usage

```javascript
var nanmskmax = require( '@stdlib/stats-array-nanmskmax' );
```

#### nanmskmax( x, mask )

Computes the maximum value of an array according to a mask, ignoring `NaN` values.

```javascript
var x = [ 1.0, -2.0, NaN, 2.0 ];
var mask = [ 0, 1, 0, 0 ];

var v = nanmskmax( x, mask );
// returns 2.0
```

The function has the following parameters:

-   **x**: input array.
-   **mask**: mask array. If a `mask` array element is `0`, the corresponding element in `x` is considered valid and **included** in computation. If a `mask` array element is `1`, the corresponding element in `x` is considered invalid/missing and **excluded** from computation.

</section>

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<section class="notes">

## Notes

-   If provided an empty array, the function returns `NaN`.
-   The function supports array-like objects having getter and setter accessors for array element access (e.g., [`@stdlib/array-base/accessor`][@stdlib/array/base/accessor]).

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var uniform = require( '@stdlib/random-base-uniform' );
var bernoulli = require( '@stdlib/random-base-bernoulli' );
var filledarrayBy = require( '@stdlib/array-filled-by' );
var nanmskmax = require( '@stdlib/stats-array-nanmskmax' );

function rand() {
    if ( bernoulli( 0.8 ) < 1 ) {
        return NaN;
    }
    return uniform( -50.0, 50.0 );
}

var x = filledarrayBy( 10, 'float64', rand );
console.log( x );

var mask = filledarrayBy( x.length, 'uint8', bernoulli.factory( 0.2 ) );
console.log( mask );

var v = nanmskmax( x, mask );
console.log( v );
```

</section>

<!-- /.examples -->

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<section class="related">

</section>

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<section class="main-repo" >

* * *

## 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].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

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

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[stdlib]: https://github.com/stdlib-js/stdlib

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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/stats-array-nanmskmax/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-array-nanmskmax/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-array-nanmskmax/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-array-nanmskmax/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-array-nanmskmax/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-array-nanmskmax/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-array-nanmskmax/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-array-nanmskmax/main/LICENSE

[@stdlib/array/base/accessor]: https://www.npmjs.com/package/@stdlib/array-base-accessor

</section>

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