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!

sort

Sort an input ndarray along one or more ndarray dimensions.

Installation

npm install @stdlib/blas-ext-sort

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md 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

var sort = require( '@stdlib/blas-ext-sort' );

sort( x[, sortOrder][, options] )

Sorts an input ndarray along one or more ndarray dimensions.

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

var x = array( [ -1.0, 2.0, -3.0 ] );

var y = sort( x );
// returns <ndarray>[ -3.0, -1.0, 2.0 ]

var bool = ( x === y );
// returns true

The function has the following parameters:

• x: input ndarray. Must have a real-valued or "generic" data type.
• sortOrder: sort order (optional). May be either a scalar value, string, or an ndarray having a real-valued or "generic" data type. If provided an ndarray, the value must have a shape which is broadcast-compatible with the complement of the shape defined by options.dims. For example, given the input shape [2, 3, 4] and options.dims=[0], an ndarray sort order must have a shape which is broadcast-compatible with the shape [3, 4]. Similarly, when performing the operation over all elements in a provided input ndarray, an ndarray sort order must be a zero-dimensional ndarray. By default, the sort order is 1 (i.e., increasing order).
• options: function options (optional).

The function accepts the following options:

• dims: list of dimensions over which to perform operation. If not provided, the function performs the operation over all elements in a provided input ndarray.

By default, the function sorts elements in increasing order. To sort in a different order, provide a sortOrder argument.

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

var x = array( [ -1.0, 2.0, -3.0 ] );

var y = sort( x, -1.0 );
// returns <ndarray>[ 2.0, -1.0, -3.0 ]

In addition to numeric values, one can specify the sort order via one of the following string literals: 'ascending', 'asc', 'descending', or 'desc'. The first two literals indicate to sort in ascending (i.e., increasing) order. The last two literals indicate to sort in descending (i.e., decreasing) order.

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

var x = array( [ -1.0, 2.0, -3.0 ] );

// Sort in ascending order:
var y = sort( x, 'asc' );
// returns <ndarray>[ -3.0, -1.0, 2.0 ]

// Sort in descending order:
y = sort( x, 'descending' );
// returns <ndarray>[ 2.0, -1.0, -3.0 ]

By default, the function performs the operation over all elements in a provided input ndarray. To perform the operation over specific dimensions, provide a dims option.

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

var x = array( [ -1.0, 2.0, -3.0, 4.0 ], {
    'shape': [ 2, 2 ],
    'order': 'row-major'
});
// returns <ndarray>[ [ -1.0, 2.0 ], [ -3.0, 4.0 ] ]

var y = sort( x, {
    'dims': [ 0 ]
});
// returns <ndarray>[ [ -3.0, 2.0 ], [ -1.0, 4.0 ] ]

Notes

• The input ndarray is sorted in-place (i.e., the input ndarray is mutated).
• If sortOrder < 0.0 or is either 'desc' or 'descending', the input ndarray is sorted in decreasing order. If sortOrder > 0.0 or is either 'asc' or 'ascending', the input ndarray is sorted in increasing order. If sortOrder == 0.0, the input ndarray is left unchanged.
• The algorithm distinguishes between -0 and +0. When sorted in increasing order, -0 is sorted before +0. When sorted in decreasing order, -0 is sorted after +0.
• The algorithm sorts NaN values to the end. When sorted in increasing order, NaN values are sorted last. When sorted in decreasing order, NaN values are sorted first.
• The function iterates over ndarray elements according to the memory layout of the input ndarray. Accordingly, performance degradation is possible when operating over multiple dimensions of a large non-contiguous multi-dimensional input ndarray. In such scenarios, one may want to copy an input ndarray to contiguous memory before sorting.

Examples

var discreteUniform = require( '@stdlib/random-discrete-uniform' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var sort = require( '@stdlib/blas-ext-sort' );

// Generate an array of random numbers:
var x = discreteUniform( [ 5, 5 ], -20, 20, {
    'dtype': 'generic'
});
console.log( ndarray2array( x ) );

// Perform operation:
sort( x, {
    'dims': [ 0 ]
});

// Print the results:
console.log( ndarray2array( x ) );

---

Notice

This package is part of 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, see the main project repository.

Community

---

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.