npm package: @stdlib/lapack-base-zlaset
Description: Set the off-diagonal elements and the diagonal elements of a double-precision complex floating-point matrix to specified values.
Author: The Stdlib Authors
Latest version: 0.1.1

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# zlaset

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> Set the off-diagonal elements and the diagonal elements of a double-precision complex floating-point matrix to specified values.

<section class="installation">

## Installation

```bash
npm install @stdlib/lapack-base-zlaset
```

</section>

<section class="usage">

## Usage

```javascript
var zlaset = require( '@stdlib/lapack-base-zlaset' );
```

#### zlaset( order, uplo, M, N, alpha, beta, A, LDA )

Sets the off-diagonal elements and the diagonal elements of a double-precision complex floating-point matrix to specified values.

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

var A = new Complex128Array( 4 );

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset( 'row-major', 'all', 2, 2, alpha, beta, A, 2 );

var z = A.get( 0 );
// returns <Complex128>[ 3.0, 4.0 ]

z = A.get( 1 );
// returns <Complex128>[ 1.0, 2.0 ]
```

The function has the following parameters:

-   **order**: storage layout.
-   **uplo**: specifies whether to set the upper or lower triangular/trapezoidal part of a matrix `A`.
-   **M**: number of rows in `A`.
-   **N**: number of columns in `A`.
-   **alpha**: value assigned to off-diagonal elements.
-   **beta**: value assigned to diagonal elements.
-   **A**: input [`Complex128Array`][@stdlib/array/complex128].
-   **LDA**: stride of the first dimension of `A` (a.k.a., leading dimension of the matrix `A`).

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

<!-- eslint-disable stdlib/capitalized-comments -->

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

// Initial array:
var A0 = new Complex128Array( 5 );

// Create offset view:
var A1 = new Complex128Array( A0.buffer, A0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset( 'row-major', 'all', 2, 2, alpha, beta, A1, 2 );

var z = A0.get( 1 );
// returns <Complex128>[ 3.0, 4.0 ]
```

#### zlaset.ndarray( uplo, M, N, alpha, beta, A, sa1, sa2, oa )

Sets the off-diagonal elements and the diagonal elements of a double-precision complex floating-point matrix to specified values using alternative indexing semantics.

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

var A = new Complex128Array( 4 );

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset.ndarray( 'all', 2, 2, alpha, beta, A, 2, 1, 0 );

var z = A.get( 0 );
// returns <Complex128>[ 3.0, 4.0 ]

z = A.get( 1 );
// returns <Complex128>[ 1.0, 2.0 ]
```

The function has the following parameters:

-   **uplo**: specifies whether to set the upper or lower triangular/trapezoidal part of a matrix `A`.
-   **M**: number of rows in `A`.
-   **N**: number of columns in `A`.
-   **alpha**: value assigned to off-diagonal elements.
-   **beta**: value assigned to diagonal elements.
-   **A**: input [`Complex128Array`][@stdlib/array/complex128].
-   **sa1**: stride of the first dimension of `A`.
-   **sa2**: stride of the second dimension of `A`.
-   **oa**: starting index for `A`.

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,

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

var A = new Complex128Array( 5 );

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset.ndarray( 'all', 2, 2, alpha, beta, A, 2, 1, 1 );

var z = A.get( 0 );
// returns <Complex128>[ 0.0, 0.0 ]

z = A.get( 1 );
// returns <Complex128>[ 3.0, 4.0 ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   `zlaset()` corresponds to the [LAPACK][lapack] routine [`zlaset`][lapack-zlaset].

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var Complex128Array = require( '@stdlib/array-complex128' );
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var ndarray2array = require( '@stdlib/ndarray-base-to-array' );
var numel = require( '@stdlib/ndarray-base-numel' );
var shape2strides = require( '@stdlib/ndarray-base-shape2strides' );
var zlaset = require( '@stdlib/lapack-base-zlaset' );

var shape = [ 5, 8 ];
var order = 'row-major';
var strides = shape2strides( shape, order );

var N = numel( shape );

var A = new Complex128Array( N );
console.log( ndarray2array( A, shape, strides, 0, order ) );

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset( order, 'all', shape[ 0 ], shape[ 1 ], alpha, beta, A, strides[ 0 ] );
console.log( ndarray2array( A, shape, strides, 0, order ) );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

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<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
TODO
```

#### TODO

TODO.

```c
TODO
```

TODO

```c
TODO
```

</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
TODO
```

</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 -->

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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].

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---

## License

See [LICENSE][stdlib-license].


## Copyright

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

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

[lapack]: https://www.netlib.org/lapack/explore-html/

[lapack-zlaset]: https://www.netlib.org/lapack/explore-html/d0/de5/group__laset_gaf2a0d5a8d17c28cb3cb1f36a77bb8537.html#gaf2a0d5a8d17c28cb3cb1f36a77bb8537

[@stdlib/array/complex128]: https://www.npmjs.com/package/@stdlib/array-complex128

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