README.md

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ssortins

Sort a single-precision floating-point strided array using insertion sort.

Usage

To use in Observable,

ssortins = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-ssortins@umd/browser.js' )

To vendor stdlib functionality and avoid installing dependency trees for Node.js, you can use the UMD server build:

var ssortins = require( 'path/to/vendor/umd/blas-ext-base-ssortins/index.js' )

To include the bundle in a webpage,

<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-ssortins@umd/browser.js"></script>

If no recognized module system is present, access bundle contents via the global scope:

<script type="text/javascript">
(function () {
    window.ssortins;
})();
</script>

ssortins( N, order, x, stride )

Sorts a single-precision floating-point strided array x using insertion sort.

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

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

ssortins( x.length, 1.0, x, 1 );
// x => <Float32Array>[ -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.
• x: input Float32Array.
• stride: index increment.

The N and stride parameters determine which elements in the strided array are accessed at runtime. For example, to sort every other element

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

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

ssortins( 2, -1.0, x, 2 );
// x => <Float32Array>[ 3.0, -2.0, 1.0, -4.0 ]

Note that indexing is relative to the first index. To introduce an offset, use typed array views.

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

// Initial array...
var x0 = new Float32Array( [ 1.0, 2.0, 3.0, 4.0 ] );

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

// Sort every other element...
ssortins( 2, -1.0, x1, 2 );
// x0 => <Float32Array>[ 1.0, 4.0, 3.0, 2.0 ]

ssortins.ndarray( N, order, x, stride, offset )

Sorts a single-precision floating-point strided array x using insertion sort and alternative indexing semantics.

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

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

ssortins.ndarray( x.length, 1.0, x, 1, 0 );
// x => <Float32Array>[ -4.0, -2.0, 1.0, 3.0 ]

The function has the following additional parameters:

• offset: starting index.

While 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 of x

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

var x = new Float32Array( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ] );

ssortins.ndarray( 3, 1.0, x, 1, x.length-3 );
// x => <Float32Array>[ 1.0, -2.0, 3.0, -6.0, -4.0, 5.0 ]

Notes

• If N <= 0 or order == 0.0, both functions return x 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 algorithm has space complexity O(1) and worst case time complexity O(N^2).
• The algorithm is efficient for small strided arrays (typically N <= 20) and is particularly efficient for sorting strided arrays which are already substantially sorted.
• The algorithm is stable, meaning that the algorithm does not change the order of strided array elements which are equal or equivalent (e.g., NaN values).
• The input strided array is sorted in-place (i.e., the input strided array is mutated).

Examples

<!DOCTYPE html>
<html lang="en">
<body>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-round@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-base-randu@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-ssortins@umd/browser.js"></script>
<script type="text/javascript">
(function () {

var rand;
var sign;
var i;

var x = new Float32Array( 10 );
for ( i = 0; i < x.length; i++ ) {
    rand = round( randu()*100.0 );
    sign = randu();
    if ( sign < 0.5 ) {
        sign = -1.0;
    } else {
        sign = 1.0;
    }
    x[ i ] = sign * rand;
}
console.log( x );

ssortins( x.length, -1.0, x, -1 );
console.log( x );

})();
</script>
</body>
</html>

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See Also

• @stdlib/blas-ext/base/dsortins: sort a double-precision floating-point strided array using insertion sort.
• @stdlib/blas-ext/base/gsortins: sort a strided array using insertion sort.
• @stdlib/blas-ext/base/ssort2ins: simultaneously sort two single-precision floating-point strided arrays based on the sort order of the first array using insertion sort.

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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

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License

See LICENSE.

Copyright

Copyright © 2016-2025. The Stdlib Authors.