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317 changes: 317 additions & 0 deletions lib/node_modules/@stdlib/blas/ext/base/sxmy/README.md
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<!--

@license Apache-2.0

Copyright (c) 2026 The Stdlib Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

-->

# sxmy

> Multiply elements of a single-precision floating-point strided array `x` by the corresponding elements of a single-precision floating-point strided array `y` and assign the results to `y`.

<section class="intro">

This BLAS extension implements the operation

<!-- <equation class="equation" label="eq:xmy" align="center" raw="\mathbf{y} = \mathbf{x} \odot \mathbf{y}" alt="Equation for xmy operation."> -->

```math
\mathbf{y} = \mathbf{x} \odot \mathbf{y}
```

<!-- </equation> -->

</section>

<!-- /.intro -->

<section class="usage">

## Usage

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

#### sxmy( N, x, strideX, y, strideY )

Multiplies elements of a single-precision floating-point strided array `x` by the corresponding elements of a single-precision floating-point strided array `y` and assigns the results to `y`.

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

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

sxmy( x.length, x, 1, y, 1 );
// y => <Float32Array>[ 2.0, 6.0, 12.0, 20.0, 30.0 ]
```

The function has the following parameters:

- **N**: number of indexed elements.
- **x**: input [`Float32Array`][@stdlib/array/float32].
- **strideX**: stride length for `x`.
- **y**: output [`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 multiply every other element of `x` by every other element of `y`:

```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( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );

sxmy( 3, x, 2, y, 2 );
// y => <Float32Array>[ 7.0, 8.0, 27.0, 10.0, 55.0, 12.0 ]
```

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, 5.0, 6.0 ] );
var y0 = new Float32Array( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );

// 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*2 ); // start at 3rd element

sxmy( 3, x1, 1, y1, 1 );
// y0 => <Float32Array>[ 7.0, 8.0, 18.0, 30.0, 44.0, 12.0 ]
```

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

Multiplies elements of a single-precision floating-point strided array `x` by the corresponding elements of a single-precision floating-point strided array `y` and assigns the results to `y` using alternative indexing semantics.

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

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

sxmy.ndarray( x.length, x, 1, 0, y, 1, 0 );
// y => <Float32Array>[ 2.0, 6.0, 12.0, 20.0, 30.0 ]
```

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 multiply the last three elements of `x` by the last three elements of `y`:

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

var x = new Float32Array( [ 1.0, 2.0, 3.0, 4.0, 5.0 ] );
var y = new Float32Array( [ 6.0, 7.0, 8.0, 9.0, 10.0 ] );

sxmy.ndarray( 3, x, 1, x.length-3, y, 1, y.length-3 );
// y => <Float32Array>[ 6.0, 7.0, 24.0, 36.0, 50.0 ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

- If `N <= 0`, both functions return `y` unchanged.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

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

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

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

sxmy( x.length, x, 1, y, 1 );
console.log( y );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<section class="intro">

</section>

<!-- /.intro -->

<section class="usage">

### Usage

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

#### stdlib_strided_sxmy( N, \*X, strideX, \*Y, strideY )

Multiplies elements of a single-precision floating-point strided array `x` by the corresponding elements of a single-precision floating-point strided array `y` and assigns the results to `y`.

```c
const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f };
float y[] = { 2.0f, 3.0f, 4.0f, 5.0f };

stdlib_strided_sxmy( 4, x, 1, y, 1 );
```

The function accepts the following arguments:

- **N**: `[in] CBLAS_INT` number of indexed elements.
- **X**: `[in] float*` input array.
- **strideX**: `[in] CBLAS_INT` stride length for `X`.
- **Y**: `[inout] float*` output array.
- **strideY**: `[in] CBLAS_INT` stride length for `Y`.

```c
void stdlib_strided_sxmy( const CBLAS_INT N, const float *X, const CBLAS_INT strideX, float *Y, const CBLAS_INT strideY );
```

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

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

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

Multiplies elements of a single-precision floating-point strided array `x` by the corresponding elements of a single-precision floating-point strided array `y` and assigns the results to `y` using alternative indexing semantics.

```c
const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f };
float y[] = { 2.0f, 3.0f, 4.0f, 5.0f };

stdlib_strided_sxmy_ndarray( 4, x, 1, 0, y, 1, 0 );
```

The function accepts the following arguments:

- **N**: `[in] CBLAS_INT` number of indexed elements.
- **X**: `[in] float*` input array.
- **strideX**: `[in] CBLAS_INT` stride length for `X`.
- **offsetX**: `[in] CBLAS_INT` starting index for `X`.
- **Y**: `[inout] float*` output array.
- **strideY**: `[in] CBLAS_INT` stride length for `Y`.
- **offsetY**: `[in] CBLAS_INT` starting index for `Y`.

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

</section>

<!-- /.usage -->

<section class="notes">

</section>

<!-- /.notes -->

<section class="examples">

### Examples

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

int main( void ) {
// Create strided arrays:
const float x[] = { 1.0f, -2.0f, 3.0f, -4.0f, 5.0f, -6.0f, 7.0f, -8.0f };
float y[] = { 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f };

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

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

// Multiply elements of `x` by the corresponding elements of `y`:
stdlib_strided_sxmy( N, x, strideX, y, strideY );

// Print the result:
for ( int i = 0; i < 8; 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">

</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">

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

[@stdlib/array/float32]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/float32

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

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

</section>

<!-- /.links -->
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