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# ssort2ins

> Simultaneously sort two single-precision floating-point strided arrays based on the sort order of the first array using insertion sort.

<section class="usage">

## Usage

```javascript
var ssort2ins = require( '@stdlib/blas/ext/base/ssort2ins' );
```

#### ssort2ins( N, order, x, strideX, y, strideY )

Simultaneously sorts two single-precision floating-point strided arrays based on the sort order of the first array using insertion sort.

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

var x = new Float32Array( [ 1.0, -2.0, 3.0, -4.0 ] );
var y = new Float32Array( [ 0.0, 1.0, 2.0, 3.0 ] );

ssort2ins( x.length, 1.0, x, 1, y, 1 );

console.log( x );
// => <Float32Array>[ -4.0, -2.0, 1.0, 3.0 ]

console.log( y );
// => <Float32Array>[ 3.0, 1.0, 0.0, 2.0 ]
```

The function has the following parameters:

-   **N**: number of indexed elements.
-   **order**: sort order. If `order < 0.0`, the input strided array `x` is sorted in **decreasing** order. If `order > 0.0`, the input strided array `x` is sorted in **increasing** order. If `order == 0.0`, the input strided arrays are left unchanged.
-   **x**: first input [`Float32Array`][@stdlib/array/float32].
-   **strideX**: stride length for `x`.
-   **y**: second input [`Float32Array`][@stdlib/array/float32].
-   **strideY**: stride length for `y`.

The `N` and stride parameters determine which elements in the strided arrays 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 ] );
var y = new Float32Array( [ 0.0, 1.0, 2.0, 3.0 ] );

ssort2ins( 2, -1.0, x, 2, y, 2 );

console.log( x );
// => <Float32Array>[ 3.0, -2.0, 1.0, -4.0 ]

console.log( y );
// => <Float32Array>[ 2.0, 1.0, 0.0, 3.0 ]
```

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 arrays...
var x0 = new Float32Array( [ 1.0, 2.0, 3.0, 4.0 ] );
var y0 = new Float32Array( [ 0.0, 1.0, 2.0, 3.0 ] );

// Create offset views...
var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var y1 = new Float32Array( y0.buffer, y0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

// Sort every other element...
ssort2ins( 2, -1.0, x1, 2, y1, 2 );

console.log( x0 );
// => <Float32Array>[ 1.0, 4.0, 3.0, 2.0 ]

console.log( y0 );
// => <Float32Array>[ 0.0, 3.0, 2.0, 1.0 ]
```

#### ssort2ins.ndarray( N, order, x, strideX, offsetX, y, strideY, offsetY )

Simultaneously sorts two single-precision floating-point strided arrays based on the sort order of the first array the strided array 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 ] );
var y = new Float32Array( [ 0.0, 1.0, 2.0, 3.0 ] );

ssort2ins.ndarray( x.length, 1.0, x, 1, 0, y, 1, 0 );

console.log( x );
// => <Float32Array>[ -4.0, -2.0, 1.0, 3.0 ]

console.log( y );
// => <Float32Array>[ 3.0, 1.0, 0.0, 2.0 ]
```

The function has the following additional parameters:

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

While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying buffer, the offset parameters support indexing semantics based on starting indices. For example, to access only the last three elements:

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

var x = new Float32Array( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ] );
var y = new Float32Array( [ 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 ] );

ssort2ins.ndarray( 3, 1.0, x, 1, x.length-3, y, 1, y.length-3 );

console.log( x );
// => <Float32Array>[ 1.0, -2.0, 3.0, -6.0, -4.0, 5.0 ]

console.log( y );
// => <Float32Array>[ 0.0, 1.0, 2.0, 5.0, 3.0, 4.0 ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   If `N <= 0` or `order == 0.0`, both functions leave `x` and `y` 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 arrays are sorted **in-place** (i.e., the input strided arrays are **mutated**).

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
var ssort2ins = require( '@stdlib/blas/ext/base/ssort2ins' );

var x = discreteUniform( 10, -100, 100, {
    'dtype': 'float32'
});
var y = discreteUniform( 10, -100, 100, {
    'dtype': 'float32'
});

console.log( x );
console.log( y );

ssort2ins( x.length, -1.0, x, -1, y, -1 );
console.log( x );
console.log( y );
```

</section>

<!-- /.examples -->

* * *

<!-- C interface documentation. -->

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/blas/ext/base/ssort2ins.h"
```

#### stdlib_strided_ssort2ins( N, order, \*X, strideX, \*Y, strideY )

Simultaneously sorts two single-precision floating-point strided arrays based on the sort order of the first array using insertion sort.

```c
float x[] = { 1.0f, -2.0f, 3.0f, -4.0f };
float y[] = { 0.0f, 1.0f, 2.0f, 3.0f };

stdlib_strided_ssort2ins( 4, 1.0f, x, 1, y, 1 );
```

The function accepts the following arguments:

-   **N**: `[in] CBLAS_INT` number of indexed elements.
-   **order**: `[in] float` sort order. If `order < 0.0`, the input strided array `X` is sorted in **decreasing** order. If `order > 0.0`, the input strided array `X` is sorted in **increasing** order. If `order == 0.0`, the input strided arrays are left unchanged.
-   **X**: `[inout] float*` first input array.
-   **strideX**: `[in] CBLAS_INT` stride length for `X`.
-   **Y**: `[inout] float*` second input array.
-   **strideY**: `[in] CBLAS_INT` stride length for `Y`.

```c
stdlib_strided_ssort2ins( const CBLAS_INT N, const float order, float *X, const CBLAS_INT strideX, float *Y, const CBLAS_INT strideY );
```

<!--lint disable maximum-heading-length-->

#### stdlib_strided_ssort2ins_ndarray( N, order, \*X, strideX, offsetX, \*Y, strideY, offsetY )

<!--lint enable maximum-heading-length-->

Simultaneously sorts two single-precision floating-point strided arrays based on the sort order of the first array using insertion sort and alternative indexing semantics.

```c
float x[] = { 1.0f, -2.0f, 3.0f, -4.0f };
float y[] = { 0.0f, 1.0f, 2.0f, 3.0f };

stdlib_strided_ssort2ins_ndarray( 4, 1.0f, x, 1, 0, y, 1, 0 );
```

The function accepts the following arguments:

-   **N**: `[in] CBLAS_INT` number of indexed elements.
-   **order**: `[in] float` sort order. If `order < 0.0`, the input strided array `X` is sorted in **decreasing** order. If `order > 0.0`, the input strided array `X` is sorted in **increasing** order. If `order == 0.0`, the input strided arrays are left unchanged.
-   **X**: `[inout] float*` first input array.
-   **strideX**: `[in] CBLAS_INT` stride length for `X`.
-   **offsetX**: `[in] CBLAS_INT` starting index for `X`.
-   **Y**: `[inout] float*` second input array.
-   **strideY**: `[in] CBLAS_INT` stride length for `Y`.
-   **offsetY**: `[in] CBLAS_INT` starting index for `Y`.

```c
stdlib_strided_ssort2ins_ndarray( const CBLAS_INT N, const float order, float *X, const CBLAS_INT strideX, const CBLAS_INT offsetX, float *Y, const CBLAS_INT strideY, const CBLAS_INT offsetY );
```

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

### Examples

```c
#include "stdlib/blas/ext/base/ssort2ins.h"
#include <stdio.h>

int main( void ) {
    // Create strided arrays:
    float x[] = { 1.0f, -2.0f, 3.0f, -4.0f, 5.0f, -6.0f, 7.0f, -8.0f };
    float y[] = { 0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f };

    // Specify the number of elements:
    int N = 8;

    // Specify the strides:
    int strideX = 1;
    int strideY = 1;

    // Sort the arrays:
    stdlib_strided_ssort2ins( N, 1.0f, x, strideX, y, strideY );

    // Print the result:
    for ( int i = 0; i < 8; i++ ) {
        printf( "x[ %i ] = %f\n", i, x[ i ] );
        printf( "y[ %i ] = %f\n", i, y[ i ] );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/blas/ext/base/dsort2ins`][@stdlib/blas/ext/base/dsort2ins]</span><span class="delimiter">: </span><span class="description">simultaneously sort two double-precision floating-point strided arrays based on the sort order of the first array using insertion sort.</span>
-   <span class="package-name">[`@stdlib/blas/ext/base/gsort2ins`][@stdlib/blas/ext/base/gsort2ins]</span><span class="delimiter">: </span><span class="description">simultaneously sort two strided arrays based on the sort order of the first array using insertion sort.</span>
-   <span class="package-name">[`@stdlib/blas/ext/base/ssortins`][@stdlib/blas/ext/base/ssortins]</span><span class="delimiter">: </span><span class="description">sort a single-precision floating-point strided array using insertion sort.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[@stdlib/array/float32]: https://www.npmjs.com/package/@stdlib/array-float32

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

<!-- <related-links> -->

[@stdlib/blas/ext/base/dsort2ins]: https://github.com/stdlib-js/blas/tree/main/ext/base/dsort2ins

[@stdlib/blas/ext/base/gsort2ins]: https://github.com/stdlib-js/blas/tree/main/ext/base/gsort2ins

[@stdlib/blas/ext/base/ssortins]: https://github.com/stdlib-js/blas/tree/main/ext/base/ssortins

<!-- </related-links> -->

</section>

<!-- /.links -->
