Skip to content

feat: add javascript implementation of blas/base/cdotc #4752

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.

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

Draft
wants to merge 13 commits into
base: develop
Choose a base branch
from
Draft
182 changes: 182 additions & 0 deletions lib/node_modules/@stdlib/blas/base/cdotc/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,182 @@
<!--

@license Apache-2.0

Copyright (c) 2025 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.

-->

# cdotc

> Calculate the dot product `x^H * y` of `x` and `y`.

<section class="intro">

The [dot product][dot-product] (or scalar product) is defined as

</section>

<!-- /.intro -->

<section class="usage">

## Usage

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

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

Calculates the dot product `x^H * y` of `x` and `y`.

```javascript
var Complex64Array = require( '@stdlib/array/complex64' );
var Complex64 = require( '@stdlib/complex/float32/ctor' );

var x = new Complex64Array( [ 7.0, -8.0, -1.0, -9.0 ] );
var y = new Complex64Array( [ 6.0, -6.0, -9.0, 5.0 ] );

var out = cdotc( x.length, x, 1, y, 1 );
// returns <Complex64>[ 54.0, -80.0 ]
```

The function has the following parameters:

- **N**: number of indexed elements.
- **x**: input [`Complex64Array`][@stdlib/array/complex64].
- **strideX**: index increment for `x`.
- **y**: input [`Complex64Array`][@stdlib/array/complex64].
- **strideY**: index increment for `y`.

The `N` and stride parameters determine which elements in the strided arrays are accessed at runtime. For example, to calculate the dot product of every other value in `x` and the first `N` elements of `y` in reverse order,

```javascript
var Complex64Array = require( '@stdlib/array/complex64' );
var Complex64 = require( '@stdlib/complex/float32/ctor' );

var x = new Complex64Array( [ -1.0, -9.0, 2.0, -8.0 ] );
var y = new Complex64Array( [ -5.0, 1.0, -6.0, 7.0 ] );

var out = cdotc( x.length, x, 1, y, -1 );
// returns <Complex64>[ -75.0, -99.0 ]
```

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

Calculates the dot product `x^H * y` of `x` and `y` using alternative indexing semantics.

```javascript
var Complex64Array = require( '@stdlib/array/complex64' );
var Complex64 = require( '@stdlib/complex/float32/ctor' );

var x = new Complex64Array( [ 7.0, -8.0, -1.0, -9.0 ] );
var y = new Complex64Array( [ 6.0, -6.0, -9.0, 5.0 ] );

var out = cdotc.ndarray( x.length, x, 1, 0, y, 1, 0 );
// returns <Complex64>[ 54.0, -80.0 ]
```

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 calculate the dot product of every other value in `x` starting from the second value with the last 2 elements in `y` in reverse order

```javascript
var Complex64Array = require( '@stdlib/array/complex64' );
var Complex64 = require( '@stdlib/complex/float32/ctor' );

var x = new Complex64Array( [ 7.0, -8.0, -1.0, -9.0 ] );
var y = new Complex64Array( [ 6.0, -6.0, -9.0, 5.0 ] );

var out = cdotc.ndarray( x.length, x, 1, 0, y, -1, y.length-1 );
// returns <Complex64>[ -55.0, 23.0 ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

- If `N <= 0`, both functions return complex64 with real and imagnary as `0.0`.
- `cdotc()` corresponds to the [BLAS][blas] level 1 function [`cdotc`][cdotc].

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var discreteUniform = require( '@stdlib/random/base/discrete-uniform' );
var filledarrayBy = require( '@stdlib/array/filled-by' );
var Complex64 = require( '@stdlib/complex/float32/ctor' );
var cdotc = require( '@stdlib/blas/base/cdotc' );

function rand() {
return new Complex64( discreteUniform( 0, 10 ), discreteUniform( 1, 5 ) );
}

var x = filledarrayBy( 10, 'complex64', rand );
console.log( x.toString() );

var y = filledarrayBy( 10, 'complex64', rand );
console.log( y.toString() );

// Perform dot product of x and y
var out = cdotc.ndarray( x.length, x, 1, 0, y, -1, y.length-1 );
console.log( out );
```

</section>

<!-- /.examples -->

<!-- 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">

[dot-product]: https://en.wikipedia.org/wiki/Dot_product

[blas]: http://www.netlib.org/blas

[cdotc]: http://www.netlib.org/lapack/explore-html/df/d28/group__single__blas__level1.html

[@stdlib/array/complex64]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/complex64

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

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

</section>

<!-- /.links -->
109 changes: 109 additions & 0 deletions lib/node_modules/@stdlib/blas/base/cdotc/benchmark/benchmark.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,109 @@
/**
* @license Apache-2.0
*
* Copyright (c) 2025 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.
*/

'use strict';

// MODULES //

var bench = require( '@stdlib/bench' );
var uniform = require( '@stdlib/random/array/uniform' );
var pow = require( '@stdlib/math/base/special/pow' );
var Complex64Array = require( '@stdlib/array/complex64' );
var isnanf = require( '@stdlib/math/base/assert/is-nanf' );
var realf = require( '@stdlib/complex/float32/real' );
var pkg = require( './../package.json' ).name;
var cdotc = require( './../lib/cdotc.js' );


// VARIABLES //

var options = {
'dtype': 'float32'
};


// FUNCTIONS //

/**
* Creates a benchmark function.
*
* @private
* @param {PositiveInteger} len - array length
* @returns {Function} benchmark function
*/
function createBenchmark( len ) {
var x;
var y;

x = new Complex64Array( uniform( len*2, -100.0, 100.0, options ) );
y = new Complex64Array( uniform( len*2, -100.0, 100.0, options ) );

return benchmark;

/**
* Benchmark function.
*
* @private
* @param {Benchmark} b - benchmark instance
*/
function benchmark( b ) {
var out;
var i;

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
out = cdotc( x.length, x, 1, y, 1 );
if ( isnanf( realf( out ) ) ) {
b.fail( 'should not return NaN' );
}
}
b.toc();
if ( isnanf( realf( out ) ) ) {
b.fail( 'should not return NaN' );
}
b.pass( 'benchmark finished' );
b.end();
}
}


// MAIN //

/**
* Main execution sequence.
*
* @private
*/
function main() {
var len;
var min;
var max;
var f;
var i;

min = 1; // 10^min
max = 6; // 10^max

for ( i = min; i <= max; i++ ) {
len = pow( 10, i );
f = createBenchmark( len );
bench( pkg+':len='+len, f );
}
}

main();
Loading