Sort a strided array using heapsort.
npm install @stdlib/blas-ext-base-gsorthpWe 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!
About stdlib...
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Sort a strided array using heapsort.
``bash`
npm install @stdlib/blas-ext-base-gsorthp
`javascript`
var gsorthp = require( '@stdlib/blas-ext-base-gsorthp' );
#### gsorthp( N, order, x, strideX )
Sorts a strided array using heapsort.
`javascript
var x = [ 1.0, -2.0, 3.0, -4.0 ];
gsorthp( x.length, 1.0, x, 1 );
// x => [ -4.0, -2.0, 1.0, 3.0 ]
`
The function has the following parameters:
- N: number of indexed elements.
- order: sort order. If order < 0.0, the input strided array is sorted in decreasing order. If order > 0.0, the input strided array is sorted in increasing order. If order == 0.0, the input strided array is left unchanged.Array
- x: input [][mdn-array] or [typed array][mdn-typed-array].
- strideX: stride length.
The N and stride parameters determine which elements in the strided array are accessed at runtime. For example, to sort every other element:
`javascript
var x = [ 1.0, -2.0, 3.0, -4.0 ];
gsorthp( 2, -1.0, x, 2 );
// x => [ 3.0, -2.0, 1.0, -4.0 ]
`
Note that indexing is relative to the first index. To introduce an offset, use [typed array][mdn-typed-array] views.
`javascript
var Float64Array = require( '@stdlib/array-float64' );
// Initial array...
var x0 = new Float64Array( [ 1.0, 2.0, 3.0, 4.0 ] );
// Create an offset view...
var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
// Sort every other element...
gsorthp( 2, -1.0, x1, 2 );
// x0 =>
`
#### gsorthp.ndarray( N, order, x, strideX, offsetX )
Sorts a strided array using heapsort and alternative indexing semantics.
`javascript
var x = [ 1.0, -2.0, 3.0, -4.0 ];
gsorthp.ndarray( x.length, 1.0, x, 1, 0 );
// x => [ -4.0, -2.0, 1.0, 3.0 ]
`
The function has the following additional parameters:
- offsetX: starting index.
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 access only the last three elements:
`javascript
var x = [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ];
gsorthp.ndarray( 3, 1.0, x, 1, x.length-3 );
// x => [ 1.0, -2.0, 3.0, -6.0, -4.0, 5.0 ]
`
- If N <= 0 or order == 0.0, both functions return x unchanged.@stdlib/array-base/accessor
- Both functions support array-like objects having getter and setter accessors for array element access (e.g., [][@stdlib/array/base/accessor]).-0
- The algorithm distinguishes between and +0. When sorted in increasing order, -0 is sorted before +0. When sorted in decreasing order, -0 is sorted after +0.NaN
- The algorithm sorts values to the end. When sorted in increasing order, NaN values are sorted last. When sorted in decreasing order, NaN values are sorted first.O(1)
- The algorithm has space complexity and time complexity O(N log2 N).NaN
- The algorithm is unstable, meaning that the algorithm may change the order of strided array elements which are equal or equivalent (e.g., values).dsorthp
- The input strided array is sorted in-place (i.e., the input strided array is mutated).
- Depending on the environment, the typed versions ([][@stdlib/blas/ext/base/dsorthp], [ssorthp][@stdlib/blas/ext/base/ssorthp], etc.) are likely to be significantly more performant.
`javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var gsorthp = require( '@stdlib/blas-ext-base-gsorthp' );
var x = discreteUniform( 10, -100, 100, {
'dtype': 'float64'
});
console.log( x );
gsorthp( x.length, -1.0, x, -1 );
console.log( x );
`
*
- Williams, John William Joseph. 1964. "Algorithm 232: Heapsort." _Communications of the ACM_ 7 (6). New York, NY, USA: Association for Computing Machinery: 347–49. doi:[10.1145/512274.512284][@williams:1964a].
- Floyd, Robert W. 1964. "Algorithm 245: Treesort." _Communications of the ACM_ 7 (12). New York, NY, USA: Association for Computing Machinery: 701. doi:[10.1145/355588.365103][@floyd:1964a].
*
- [@stdlib/blas-ext/base/dsorthp][@stdlib/blas/ext/base/dsorthp]: sort a double-precision floating-point strided array using heapsort.
- [@stdlib/blas-ext/base/gsort2hp][@stdlib/blas/ext/base/gsort2hp]: simultaneously sort two strided arrays based on the sort order of the first array using heapsort.
- [@stdlib/blas-ext/base/ssorthp][@stdlib/blas/ext/base/ssorthp]: sort a single-precision floating-point strided array using heapsort.
*
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]
---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/blas-ext-base-gsorthp.svg
[npm-url]: https://npmjs.org/package/@stdlib/blas-ext-base-gsorthp
[test-image]: https://github.com/stdlib-js/blas-ext-base-gsorthp/actions/workflows/test.yml/badge.svg?branch=v0.3.1
[test-url]: https://github.com/stdlib-js/blas-ext-base-gsorthp/actions/workflows/test.yml?query=branch:v0.3.1
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/blas-ext-base-gsorthp/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/blas-ext-base-gsorthp?branch=main
[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
[chat-url]: https://stdlib.zulipchat.com
[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/blas-ext-base-gsorthp/tree/deno
[deno-readme]: https://github.com/stdlib-js/blas-ext-base-gsorthp/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/blas-ext-base-gsorthp/tree/umd
[umd-readme]: https://github.com/stdlib-js/blas-ext-base-gsorthp/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/blas-ext-base-gsorthp/tree/esm
[esm-readme]: https://github.com/stdlib-js/blas-ext-base-gsorthp/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/blas-ext-base-gsorthp/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/blas-ext-base-gsorthp/main/LICENSE
[mdn-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
[@stdlib/array/base/accessor]: https://www.npmjs.com/package/@stdlib/array-base-accessor
[@williams:1964a]: https://doi.org/10.1145/512274.512284
[@floyd:1964a]: https://doi.org/10.1145/355588.365103
[@stdlib/blas/ext/base/dsorthp]: https://www.npmjs.com/package/@stdlib/blas-ext-base-dsorthp
[@stdlib/blas/ext/base/gsort2hp]: https://www.npmjs.com/package/@stdlib/blas-ext-base-gsort2hp
[@stdlib/blas/ext/base/ssorthp]: https://www.npmjs.com/package/@stdlib/blas-ext-base-ssorthp