Skip to content

feat: add blas/ext/base/zaxpb #12342

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kgryte merged 1 commit into from
May 29, 2026
Merged

feat: add blas/ext/base/zaxpb #12342

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
335 changes: 335 additions & 0 deletions lib/node_modules/@stdlib/blas/ext/base/zaxpb/README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,335 @@
<!--

@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.

-->

# zaxpb

> Multiply each element in a double-precision complex floating-point strided array by a scalar constant and add a scalar constant to each result.

<section class="usage">

## Usage

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

#### zaxpb( N, alpha, beta, x, strideX )

Multiplies each element in a double-precision complex floating-point strided array by a scalar constant and adds a scalar constant to each result.

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

var x = new Complex128Array( [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );

var alpha = new Complex128( 2.0, 0.0 );
var beta = new Complex128( 1.0, 0.0 );

zaxpb( x.length, alpha, beta, x, 1 );
// x => <Complex128Array>[ -3.0, 2.0, 7.0, -10.0, 9.0, 0.0, -1.0, -6.0 ]
```

The function has the following parameters:

- **N**: number of indexed elements.
- **alpha**: first scalar constant.
- **beta**: second scalar constant.
- **x**: input [`Complex128Array`][@stdlib/array/complex128].
- **strideX**: stride length.

The `N` and stride parameters determine which elements in the strided array are accessed at runtime. For example, to multiply every other element by `alpha` and add `beta`:

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

var x = new Complex128Array( [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );

var alpha = new Complex128( 2.0, 0.0 );
var beta = new Complex128( 1.0, 0.0 );

zaxpb( 2, alpha, beta, x, 2 );
// x => <Complex128Array>[ -3.0, 2.0, 3.0, -5.0, 9.0, 0.0, -1.0, -3.0 ]
```

Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views.

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

// Initial array:
var x0 = new Complex128Array( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0, 7.0, -8.0 ] );

// Create an offset view:
var x1 = new Complex128Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

// Define scalar constants:
var alpha = new Complex128( 2.0, 0.0 );
var beta = new Complex128( 1.0, 0.0 );

// Multiply every other element by alpha and add beta starting from the second element:
zaxpb( 2, alpha, beta, x1, 2 );
// x0 => <Complex128Array>[ 1.0, -2.0, 7.0, -8.0, 5.0, -6.0, 15.0, -16.0 ]
```

#### zaxpb.ndarray( N, alpha, beta, x, strideX, offsetX )

Multiplies each element in a double-precision complex floating-point strided array by a scalar constant and adds a scalar constant to each result using alternative indexing semantics.

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

var x = new Complex128Array( [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );

var alpha = new Complex128( 2.0, 0.0 );
var beta = new Complex128( 1.0, 0.0 );

zaxpb.ndarray( x.length, alpha, beta, x, 1, 0 );
// x => <Complex128Array>[ -3.0, 2.0, 7.0, -10.0, 9.0, 0.0, -1.0, -6.0 ]
```

The function has the following additional parameters:

- **offsetX**: 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 two elements of the strided array:

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

var x = new Complex128Array( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ] );

var alpha = new Complex128( 2.0, 0.0 );
var beta = new Complex128( 1.0, 0.0 );

zaxpb.ndarray( 2, alpha, beta, x, 1, 1 );
// x => <Complex128Array>[ 1.0, -2.0, 7.0, -8.0, 11.0, -12.0 ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

- If `N <= 0`, both functions return the strided array unchanged.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var logEach = require( '@stdlib/console/log-each' );
var zaxpb = require( '@stdlib/blas/ext/base/zaxpb' );

var xbuf = discreteUniform( 20, -100, 100, {
'dtype': 'float64'
});
var x = new Complex128Array( xbuf.buffer );
var alpha = new Complex128( 2.0, 1.0 );
var beta = new Complex128( 5.0, -3.0 );

zaxpb( x.length, alpha, beta, x, 1 );
logEach( '%s', x );
```

</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/zaxpb.h"
```

#### stdlib_strided_zaxpb( N, alpha, beta, \*X, strideX )

Multiplies each element in a double-precision complex floating-point strided array by a scalar constant and adds a scalar constant to each result.

```c
#include "stdlib/complex/float64/ctor.h"

double x[] = { 1.0, -2.0, 3.0, -4.0, 5.0, -6.0, 7.0, -8.0 };
const stdlib_complex128_t alpha = stdlib_complex128( 2.0, 0.0 );
const stdlib_complex128_t beta = stdlib_complex128( 1.0, 0.0 );

stdlib_strided_zaxpb( 4, alpha, beta, (stdlib_complex128_t *)x, 1 );
```

The function accepts the following arguments:

- **N**: `[in] CBLAS_INT` number of indexed elements.
- **alpha**: `[in] stdlib_complex128_t` first scalar constant.
- **beta**: `[in] stdlib_complex128_t` second scalar constant.
- **X**: `[inout] stdlib_complex128_t*` input array.
- **strideX**: `[in] CBLAS_INT` stride length for `X`.

```c
void stdlib_strided_zaxpb( const CBLAS_INT N, const stdlib_complex128_t alpha, const stdlib_complex128_t beta, stdlib_complex128_t *X, const CBLAS_INT strideX );
```

#### stdlib_strided_zaxpb_ndarray( N, alpha, beta, \*X, strideX, offsetX )

Multiplies each element in a double-precision complex floating-point strided array by a scalar constant and adds a scalar constant to each result using alternative indexing semantics.

```c
#include "stdlib/complex/float64/ctor.h"

double x[] = { 1.0, -2.0, 3.0, -4.0, 5.0, -6.0, 7.0, -8.0 };
const stdlib_complex128_t alpha = stdlib_complex128( 2.0, 0.0 );
const stdlib_complex128_t beta = stdlib_complex128( 1.0, 0.0 );

stdlib_strided_zaxpb_ndarray( 4, alpha, beta, (stdlib_complex128_t *)x, 1, 0 );
```

The function accepts the following arguments:

- **N**: `[in] CBLAS_INT` number of indexed elements.
- **alpha**: `[in] stdlib_complex128_t` first scalar constant.
- **beta**: `[in] stdlib_complex128_t` second scalar constant.
- **X**: `[inout] stdlib_complex128_t*` input array.
- **strideX**: `[in] CBLAS_INT` stride length for `X`.
- **offsetX**: `[in] CBLAS_INT` starting index for `X`.

```c
void stdlib_strided_zaxpb_ndarray( const CBLAS_INT N, const stdlib_complex128_t alpha, const stdlib_complex128_t beta, stdlib_complex128_t *X, const CBLAS_INT strideX, const CBLAS_INT offsetX );
```

</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/zaxpb.h"
#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/real.h"
#include "stdlib/complex/float64/imag.h"
#include <stdio.h>

int main( void ) {
// Create a strided array:
stdlib_complex128_t x[] = {
stdlib_complex128( 1.0, -2.0 ),
stdlib_complex128( 3.0, -4.0 ),
stdlib_complex128( 5.0, -6.0 ),
stdlib_complex128( 7.0, -8.0 )
};

// Specify the number of indexed elements:
const int N = 4;

// Specify a stride:
const int strideX = 1;

// Define scalar constants:
stdlib_complex128_t alpha = stdlib_complex128( 2.0, 0.0 );
stdlib_complex128_t beta = stdlib_complex128( 1.0, 0.0 );

// Multiply each element by alpha and add beta:
stdlib_strided_zaxpb( N, alpha, beta, x, strideX );

// Print the result:
for ( int i = 0; i < N; i++ ) {
printf( "x[ %i ] = %lf + %lfi\n", i, stdlib_complex128_real( x[ i ] ), stdlib_complex128_imag( x[ 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">

[@stdlib/array/complex128]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/complex128

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

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

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

</section>

<!-- /.links -->
Loading