Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/stdlib-js/stats-base-smaxabs

Calculate the maximum absolute value of a single-precision floating-point strided array.
https://github.com/stdlib-js/stats-base-smaxabs

abs absolute domain extent extremes javascript math mathematics max maximum node node-js nodejs range statistics stats stdlib strided strided-array typed

Last synced: 16 days ago
JSON representation

Calculate the maximum absolute value of a single-precision floating-point strided array.

Host: GitHub
URL: https://github.com/stdlib-js/stats-base-smaxabs
Owner: stdlib-js
License: apache-2.0
Created: 2021-06-15T16:17:29.000Z (over 3 years ago)
Default Branch: main
Last Pushed: 2025-01-08T19:48:11.000Z (16 days ago)
Last Synced: 2025-01-08T20:38:24.900Z (16 days ago)
Topics: abs, absolute, domain, extent, extremes, javascript, math, mathematics, max, maximum, node, node-js, nodejs, range, statistics, stats, stdlib, strided, strided-array, typed
Language: JavaScript
Homepage: https://github.com/stdlib-js/stdlib
Size: 625 KB
Stars: 2
Watchers: 3
Forks: 0
Open Issues: 0
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Citation: CITATION.cff
- Security: SECURITY.md

Awesome Lists containing this project

README

        

  

    About stdlib...

  

  
We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

  The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

  When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

  To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!


# smaxabs

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

> Calculate the maximum absolute value of a single-precision floating-point strided array.

## Installation

```bash

npm install @stdlib/stats-base-smaxabs

```

Alternatively,

-   To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).

-   If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).

-   For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).

The [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

## Usage

```javascript

var smaxabs = require( '@stdlib/stats-base-smaxabs' );

```

#### smaxabs( N, x, strideX )

Computes the maximum absolute value of a single-precision floating-point strided array `x`.

```javascript

var Float32Array = require( '@stdlib/array-float32' );

var x = new Float32Array( [ 1.0, -2.0, 2.0 ] );

var v = smaxabs( x.length, x, 1 );

// returns 2.0

```

The function has the following parameters:

-   **N**: number of indexed elements.

-   **x**: input [`Float32Array`][@stdlib/array/float32].

-   **strideX**: stride length.

The `N` and stride parameters determine which elements in `x` are accessed at runtime. For example, to compute the maximum absolute value of every other element in `x`,

```javascript

var Float32Array = require( '@stdlib/array-float32' );

var x = new Float32Array( [ 1.0, 2.0, 2.0, -7.0, -2.0, 3.0, 4.0, 2.0 ] );

var v = smaxabs( 4, x, 2 );

// returns 4.0

```

Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views.

```javascript

var Float32Array = require( '@stdlib/array-float32' );

var x0 = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );

var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

var v = smaxabs( 4, x1, 2 );

// returns 4.0

```

#### smaxabs.ndarray( N, x, strideX, offsetX )

Computes the maximum absolute value of a single-precision floating-point strided array using alternative indexing semantics.

```javascript

var Float32Array = require( '@stdlib/array-float32' );

var x = new Float32Array( [ 1.0, -2.0, 2.0 ] );

var v = smaxabs.ndarray( x.length, x, 1, 0 );

// returns 2.0

```

The function has the following additional parameters:

-   **offsetX**: starting index for `x`.

While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying buffer, the offset parameter supports indexing semantics based on a starting index. For example, to calculate the maximum absolute value for every other element in `x` starting from the second element

```javascript

var Float32Array = require( '@stdlib/array-float32' );

var x = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );

var v = smaxabs.ndarray( 4, x, 2, 1 );

// returns 4.0

```

## Notes

-   If `N <= 0`, both functions return `NaN`.

## Examples

```javascript

var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );

var smaxabs = require( '@stdlib/stats-base-smaxabs' );

var x = discreteUniform( 10, -50, 50, {

    'dtype': 'float32'

});

console.log( x );

var v = smaxabs( x.length, x, 1 );

console.log( v );

```

* * *

## C APIs

### Usage

```c

#include "stdlib/stats/base/smaxabs.h"

```

#### stdlib_strided_smaxabs( N, \*X, strideX )

Computes the maximum absolute value of a single-precision floating-point strided array.

```c

const float x[] = { 1.0f, -2.0f, 3.0f, -4.0f };

float v = stdlib_strided_smaxabs( 4, x, 1 );

// returns 4.0f

```

The function accepts the following arguments:

-   **N**: `[in] CBLAS_INT` number of indexed elements.

-   **X**: `[in] float*` input array.

-   **strideX**: `[in] CBLAS_INT` stride length for `X`.

```c

float stdlib_strided_smaxabs( const CBLAS_INT N, const float *X, const CBLAS_INT strideX );

```

#### stdlib_strided_smaxabs_ndarray( N, \*X, strideX, offsetX )

Computes the maximum absolute value of a single-precision floating-point strided array using alternative indexing semantics.

```c

const float x[] = { 1.0f, -2.0f, 3.0f, -4.0f };

float v = stdlib_strided_smaxabs_ndarray( 4, x, 1, 0 );

// returns 4.0f

```

The function accepts the following arguments:

-   **N**: `[in] CBLAS_INT` number of indexed elements.

-   **X**: `[in] float*` input array.

-   **strideX**: `[in] CBLAS_INT` stride length for `X`.

-   **offsetX**: `[in] CBLAS_INT` starting index for `X`.

```c

float stdlib_strided_smaxabs_ndarray( const CBLAS_INT N, const float *X, const CBLAS_INT strideX, const CBLAS_INT offsetX );

```

### Examples

```c

#include "stdlib/stats/base/smaxabs.h"

#include 

int main( void ) {

    // Create a strided array:

    const float x[] = { 1.0f, -2.0f, -3.0f, 4.0f, -5.0f, -6.0f, 7.0f, 8.0f };

    // Specify the number of elements:

    const int N = 4;

    // Specify the stride length:

    const int strideX = 2;

    // Compute the maximum absolute value:

    float v = stdlib_strided_smaxabs( N, x, strideX );

    // Print the result:

    printf( "maxabs: %f\n", v );

}

```

* * *

## See Also

-   [`@stdlib/stats-base/dmaxabs`][@stdlib/stats/base/dmaxabs]: calculate the maximum absolute value of a double-precision floating-point strided array.

-   [`@stdlib/stats-base/maxabs`][@stdlib/stats/base/maxabs]: calculate the maximum absolute value of a strided array.

-   [`@stdlib/stats-base/smax`][@stdlib/stats/base/smax]: calculate the maximum value of a single-precision floating-point strided array.

-   [`@stdlib/stats-base/sminabs`][@stdlib/stats/base/sminabs]: calculate the minimum absolute value of a single-precision floating-point strided array.

-   [`@stdlib/stats-base/snanmaxabs`][@stdlib/stats/base/snanmaxabs]: calculate the maximum absolute value of a single-precision floating-point strided array, ignoring NaN values.

* * *

## 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 © 2016-2025. The Stdlib [Authors][stdlib-authors].

[npm-image]: http://img.shields.io/npm/v/@stdlib/stats-base-smaxabs.svg

[npm-url]: https://npmjs.org/package/@stdlib/stats-base-smaxabs

[test-image]: https://github.com/stdlib-js/stats-base-smaxabs/actions/workflows/test.yml/badge.svg?branch=main

[test-url]: https://github.com/stdlib-js/stats-base-smaxabs/actions/workflows/test.yml?query=branch:main

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/stats-base-smaxabs/main.svg

[coverage-url]: https://codecov.io/github/stdlib-js/stats-base-smaxabs?branch=main

[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg

[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im

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

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[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-base-smaxabs/tree/deno

[deno-readme]: https://github.com/stdlib-js/stats-base-smaxabs/blob/deno/README.md

[umd-url]: https://github.com/stdlib-js/stats-base-smaxabs/tree/umd

[umd-readme]: https://github.com/stdlib-js/stats-base-smaxabs/blob/umd/README.md

[esm-url]: https://github.com/stdlib-js/stats-base-smaxabs/tree/esm

[esm-readme]: https://github.com/stdlib-js/stats-base-smaxabs/blob/esm/README.md

[branches-url]: https://github.com/stdlib-js/stats-base-smaxabs/blob/main/branches.md

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

[@stdlib/array/float32]: https://github.com/stdlib-js/array-float32

[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray

[@stdlib/stats/base/dmaxabs]: https://github.com/stdlib-js/stats-base-dmaxabs

[@stdlib/stats/base/maxabs]: https://github.com/stdlib-js/stats-base-maxabs

[@stdlib/stats/base/smax]: https://github.com/stdlib-js/stats-base-smax

[@stdlib/stats/base/sminabs]: https://github.com/stdlib-js/stats-base-sminabs

[@stdlib/stats/base/snanmaxabs]: https://github.com/stdlib-js/stats-base-snanmaxabs