## Usage ```javascript var ssortins = require( '@stdlib/blas/ext/base/ssortins' ); ``` #### ssortins( N, order, x, stride ) Sorts a single-precision floating-point strided array `x` using insertion sort. ```javascript 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 => [ -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`][@stdlib/array/float32]. - **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 ```javascript 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 => [ 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 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 => [ 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. ```javascript 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 => [ -4.0, -2.0, 1.0, 3.0 ] ``` The function has the following additional parameters: - **offset**: 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 of `x` ```javascript 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 => [ 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 ```javascript var round = require( '@stdlib/math/base/special/round' ); var randu = require( '@stdlib/random/base/randu' ); var Float32Array = require( '@stdlib/array/float32' ); var ssortins = require( '@stdlib/blas/ext/base/ssortins' ); 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 ); ```