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

Set the off-diagonal elements and the diagonal elements of a double-precision complex floating-point matrix to specified values.
https://github.com/stdlib-js/lapack-base-zlaset

algebra array complex copy double float64 float64array javascript lapack linear math mathematics matrix ndarray node node-js nodejs stdlib subroutines 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.

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README 

        



  

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# zlaset



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



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



## Installation



```bash

npm install @stdlib/lapack-base-zlaset

```



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 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 real = require( '@stdlib/complex-float64-real' );

var imag = require( '@stdlib/complex-float64-imag' );



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 



var re = real( z );

// returns 3.0



var im = imag( z );

// returns 4.0



z = A.get( 1 );

// returns 



re = real( z );

// returns 1.0



im = imag( z );

// returns 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.



```javascript

var Complex128Array = require( '@stdlib/array-complex128' );

var Complex128 = require( '@stdlib/complex-float64-ctor' );

var real = require( '@stdlib/complex-float64-real' );

var imag = require( '@stdlib/complex-float64-imag' );



// 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 



var re = real( z );

// returns 3.0



var im = imag( z );

// returns 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 real = require( '@stdlib/complex-float64-real' );

var imag = require( '@stdlib/complex-float64-imag' );



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 



var re = real( z );

// returns 3.0



var im = imag( z );

// returns 4.0



z = A.get( 1 );

// returns 



re = real( z );

// returns 1.0



im = imag( z );

// returns 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 real = require( '@stdlib/complex-float64-real' );

var imag = require( '@stdlib/complex-float64-imag' );



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 



var re = real( z );

// returns 0.0



var im = imag( z );

// returns 0.0



z = A.get( 1 );

// returns 



re = real( z );

// returns 3.0



im = imag( z );

// returns 4.0

```



## Notes



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



## Examples



```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 ) );

```



* * *



## C APIs



### Usage



```c

TODO

```



#### TODO



TODO.



```c

TODO

```



TODO



```c

TODO

```



### Examples



```c

TODO

```



* * *



## 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-zlaset.svg

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



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

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



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

[coverage-url]: https://codecov.io/github/stdlib-js/lapack-base-zlaset?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-zlaset/tree/deno

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

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

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

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

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

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



[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://github.com/stdlib-js/array-complex128



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