npm package: @stdlib/blas-base-drotg
Description: Construct a Givens plane rotation.
Author: The Stdlib Authors
Latest version: 0.2.3

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# drotg

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

> Construct a Givens plane rotation.

<section class="installation">

## Installation

```bash
npm install @stdlib/blas-base-drotg
```

</section>

<section class="usage">

## Usage

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

#### drotg( a, b )

Constructs a Givens plane rotation provided two double-precision floating-point values `a` and `b`.

```javascript
var out = drotg( 0.0, 2.0 );
// returns <Float64Array>[ 2.0, 1.0, 0.0, 1.0 ]
```

The function has the following parameters:

-   **a**: rotational elimination parameter.
-   **b**: rotational elimination parameter.

#### drotg.assign( a, b, out, stride, offset )

Constructs a Givens plane rotation provided two double-precision floating-point values `a` and `b` and assigns results to an output array.

```javascript
var Float64Array = require( '@stdlib/array-float64' );

var out = new Float64Array( 4 );

var y = drotg.assign( 0.0, 2.0, out, 1, 0 );
// returns <Float64Array>[ 2.0, 1.0, 0.0, 1.0 ]

var bool = ( y === out );
// returns true
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   `drotg()` corresponds to the [BLAS][blas] level 1 function [`drotg`][blas-drotg].

</section>

<!-- /.notes -->

<section class="examples">

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

var out;
var i;

for ( i = 0; i < 100; i++ ) {
    out = drotg( discreteUniform( -5, 5 ), discreteUniform( -5, 5 ) );
    console.log( out );
}
```

</section>

<!-- /.examples -->

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<section class="related">

</section>

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<section class="main-repo" >

* * *

## 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 &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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[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/blas-base-drotg/tree/deno
[deno-readme]: https://github.com/stdlib-js/blas-base-drotg/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/blas-base-drotg/tree/umd
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[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/blas-base-drotg/main/LICENSE

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

[blas-drotg]: https://www.netlib.org/lapack/explore-html/d7/dc5/group__rotg_gaafa91c51f75df6c3f2182032a221c2db.html#gaafa91c51f75df6c3f2182032a221c2db

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