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https://github.com/stdlib-js/lapack-base-clacgv

Conjugate each element in a single-precision complex floating-point vector.
https://github.com/stdlib-js/lapack-base-clacgv

algebra array blas clacgv complex conjugate javascript lapack level-1 linear math mathematics ndarray node node-js nodejs stdlib subroutines typed vector

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Conjugate each element in a single-precision complex floating-point vector.

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README 

        



  

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# clacgv



[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] 



> Conjugate each element in a single-precision complex floating-point vector.



## Installation



```bash

npm install @stdlib/lapack-base-clacgv

```



Alternatively,



-   To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).

-   If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).

-   For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).



The [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.



To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.



## Usage



```javascript

var clacgv = require( '@stdlib/lapack-base-clacgv' );

```



#### clacgv( N, cx, strideCX )



Conjugates each element in a single-precision complex floating-point vector.



```javascript

var Complex64Array = require( '@stdlib/array-complex64' );

var realf = require( '@stdlib/complex-float32-real' );

var imagf = require( '@stdlib/complex-float32-imag' );



var cx = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0 ] );



clacgv( 2, cx, 1 );



var z = cx.get( 0 );

// returns 



var re = realf( z );

// returns 1.0



var im = imagf( z );

// returns -2.0

```



The function has the following parameters:



-   **N**: number of indexed elements.

-   **cx**: input [`Complex64Array`][@stdlib/array/complex64].

-   **strideCX**: stride length for `cx`.



The `N` and stride parameters determine which elements in `cx` are conjugated. For example, to conjugate every other element in `cx`,



```javascript

var Complex64Array = require( '@stdlib/array-complex64' );

var realf = require( '@stdlib/complex-float32-real' );

var imagf = require( '@stdlib/complex-float32-imag' );



var cx = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );



clacgv( 2, cx, 2 );



var z = cx.get( 0 );

// returns 



var re = realf( z );

// returns 1.0



var im = imagf( z );

// returns -2.0

```



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



```javascript

var Complex64Array = require( '@stdlib/array-complex64' );

var Complex64 = require( '@stdlib/complex-float32-ctor' );

var realf = require( '@stdlib/complex-float32-real' );

var imagf = require( '@stdlib/complex-float32-imag' );



// Initial array:

var cx0 = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );



// Create an offset view:

var cx1 = new Complex64Array( cx0.buffer, cx0.BYTES_PER_ELEMENT*1 ); // start at 2nd element



// Conjugate every element in `cx1`:

clacgv( 3, cx1, 1 );



var z = cx0.get( 1 );

// returns 



var re = realf( z );

// returns 3.0



var im = imagf( z );

// returns -4.0

```



#### clacgv.ndarray( N, cx, strideCX, offsetCX )



Conjugates each element in a single-precision floating-point vector using alternative indexing semantics.



```javascript

var Complex64Array = require( '@stdlib/array-complex64' );

var realf = require( '@stdlib/complex-float32-real' );

var imagf = require( '@stdlib/complex-float32-imag' );



var cx = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );



clacgv.ndarray( 3, cx, 1, 0 );



var z = cx.get( 0 );

// returns 



var re = realf( z );

// returns 1.0



var im = imagf( z );

// returns -2.0

```



The function has the following additional parameters:



-   **offsetCX**: starting index for `cx`.



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 conjugate every other element in the input strided array starting from the second element,



```javascript

var Complex64Array = require( '@stdlib/array-complex64' );

var realf = require( '@stdlib/complex-float32-real' );

var imagf = require( '@stdlib/complex-float32-imag' );



var cx = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );



clacgv.ndarray( 2, cx, 2, 1 );



var z = cx.get( 3 );

// returns 



var re = realf( z );

// returns 7.0



var im = imagf( z );

// returns -8.0

```



## Notes



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

-   `clacgv()` corresponds to the [LAPACK][lapack] BLAS-like level 1 routine [`clacgv`][clacgv].



## Examples



```javascript

var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );

var filledarrayBy = require( '@stdlib/array-filled-by' );

var Complex64 = require( '@stdlib/complex-float32-ctor' );

var clacgv = require( '@stdlib/lapack-base-clacgv' );



function rand() {

    return new Complex64( discreteUniform( 0, 10 ), discreteUniform( -5, 5 ) );

}



var cx = filledarrayBy( 10, 'complex64', rand );

console.log( cx.toString() );



// Conjugate elements:

clacgv( cx.length, cx, 1 );

console.log( cx.get( cx.length-1 ).toString() );

```



* * *



## Notice



This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.



For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].



#### Community



[![Chat][chat-image]][chat-url]



---



## License



See [LICENSE][stdlib-license].



## Copyright



Copyright © 2016-2025. The Stdlib [Authors][stdlib-authors].



[npm-image]: http://img.shields.io/npm/v/@stdlib/lapack-base-clacgv.svg

[npm-url]: https://npmjs.org/package/@stdlib/lapack-base-clacgv



[test-image]: https://github.com/stdlib-js/lapack-base-clacgv/actions/workflows/test.yml/badge.svg?branch=main

[test-url]: https://github.com/stdlib-js/lapack-base-clacgv/actions/workflows/test.yml?query=branch:main



[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/lapack-base-clacgv/main.svg

[coverage-url]: https://codecov.io/github/stdlib-js/lapack-base-clacgv?branch=main



[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg

[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im



[stdlib]: https://github.com/stdlib-js/stdlib



[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors



[umd]: https://github.com/umdjs/umd

[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules



[deno-url]: https://github.com/stdlib-js/lapack-base-clacgv/tree/deno

[deno-readme]: https://github.com/stdlib-js/lapack-base-clacgv/blob/deno/README.md

[umd-url]: https://github.com/stdlib-js/lapack-base-clacgv/tree/umd

[umd-readme]: https://github.com/stdlib-js/lapack-base-clacgv/blob/umd/README.md

[esm-url]: https://github.com/stdlib-js/lapack-base-clacgv/tree/esm

[esm-readme]: https://github.com/stdlib-js/lapack-base-clacgv/blob/esm/README.md

[branches-url]: https://github.com/stdlib-js/lapack-base-clacgv/blob/main/branches.md



[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/lapack-base-clacgv/main/LICENSE



[lapack]: https://www.netlib.org/lapack



[clacgv]: https://www.netlib.org/lapack/explore-html/d9/d50/group__lacgv_ga689d8db6749fa9b193ff8520bfd6b2e9.html#ga689d8db6749fa9b193ff8520bfd6b2e9



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



[@stdlib/array/complex64]: https://github.com/stdlib-js/array-complex64