npm package: @stdlib/lapack-base-zlacpy
Description: Copy all or part of a matrix A to another matrix B.
Author: The Stdlib Authors
Latest version: 0.1.1

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# zlacpy

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

> Copy all or part of a matrix `A` to another matrix `B`.

<section class="installation">

## Installation

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

</section>

<section class="usage">

## Usage

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

#### zlacpy( order, uplo, M, N, A, LDA, B, LDB )

Copies all or part of a matrix `A` to another matrix `B`.

```javascript
var Complex128Array = require( '@stdlib/array-complex128' );
var reinterpret = require( '@stdlib/strided-base-reinterpret-complex128' );

var A = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var B = new Complex128Array( 4 );

zlacpy( 'row-major', 'all', 2, 2, A, 2, B, 2 );

var viewB = reinterpret( B, 0 );
// returns <Float64Array>[ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ]
```

The function has the following parameters:

-   **order**: storage layout.
-   **uplo**: specifies whether to copy the upper or lower triangular/trapezoidal part of a matrix `A`.
-   **M**: number of rows in `A`.
-   **N**: number of columns in `A`.
-   **A**: input [`Complex128Array`][@stdlib/array/complex128].
-   **LDA**: stride of the first dimension of `A` (a.k.a., leading dimension of the matrix `A`).
-   **B**: output [`Complex128Array`][@stdlib/array/complex128].
-   **LDB**: stride of the first dimension of `B` (a.k.a., leading dimension of the matrix `B`).

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, max-len -->

```javascript
var Complex128Array = require( '@stdlib/array-complex128' );
var reinterpret = require( '@stdlib/strided-base-reinterpret-complex128' );

// Initial arrays...
var A0 = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 ] );
var B0 = new Complex128Array( 5 );

// Create offset views...
var A1 = new Complex128Array( A0.buffer, A0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var B1 = new Complex128Array( B0.buffer, B0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

zlacpy( 'row-major', 'all', 2, 2, A1, 2, B1, 2 );

var viewB = reinterpret( B0, 0 );
// returns <Float64Array>[ 0.0, 0.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 ]
```

#### zlacpy.ndarray( uplo, M, N, A, sa1, sa2, oa, B, sb1, sb2, ob )

Copies all or part of a matrix `A` to another matrix `B` using alternative indexing semantics.

```javascript
var Complex128Array = require( '@stdlib/array-complex128' );
var reinterpret = require( '@stdlib/strided-base-reinterpret-complex128' );

var A = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var B = new Complex128Array( 4 );

zlacpy.ndarray( 'all', 2, 2, A, 2, 1, 0, B, 2, 1, 0 );

var viewB = reinterpret( B, 0 );
// returns <Float64Array>[ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ]
```

The function has the following parameters:

-   **uplo**: specifies whether to copy the upper or lower triangular/trapezoidal part of a matrix `A`.
-   **M**: number of rows in `A`.
-   **N**: number of columns in `A`.
-   **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`.
-   **B**: output [`Complex128Array`][@stdlib/array/complex128].
-   **sb1**: stride of the first dimension of `B`.
-   **sb2**: stride of the second dimension of `B`.
-   **ob**: starting index for `B`.

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,

<!-- eslint-disable max-len -->

```javascript
var Complex128Array = require( '@stdlib/array-complex128' );
var reinterpret = require( '@stdlib/strided-base-reinterpret-complex128' );

var A = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 ] );
var B = new Complex128Array( 6 );

zlacpy.ndarray( 'all', 2, 2, A, 2, 1, 1, B, 2, 1, 2 );

var viewB = reinterpret( B, 0 );
// returns <Float64Array>[ 0.0, 0.0, 0.0, 0.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

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

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var Complex128Array = require( '@stdlib/array-complex128' );
var ndarray2array = require( '@stdlib/ndarray-base-to-array' );
var uniform = require( '@stdlib/random-array-discrete-uniform' );
var numel = require( '@stdlib/ndarray-base-numel' );
var shape2strides = require( '@stdlib/ndarray-base-shape2strides' );
var zlacpy = require( '@stdlib/lapack-base-zlacpy' );

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

var N = numel( shape );

var A = new Complex128Array( uniform( 2*N, -10, 10, {
    'dtype': 'generic'
}));
console.log( ndarray2array( A, shape, strides, 0, order ) );

var B = new Complex128Array( uniform( 2*N, -10, 10, {
    'dtype': 'generic'
}));
console.log( ndarray2array( B, shape, strides, 0, order ) );

zlacpy( order, 'all', shape[ 0 ], shape[ 1 ], A, strides[ 0 ], B, strides[ 0 ] );
console.log( ndarray2array( B, shape, strides, 0, order ) );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<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].

#### Community

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

---

## License

See [LICENSE][stdlib-license].


## Copyright

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

</section>

<!-- /.stdlib -->

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

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

[lapack-zlacpy]: https://netlib.org/lapack/explore-html/d0/d9e/group__lacpy_ga243f0a47458b9a525136a69146c10192.html#ga243f0a47458b9a525136a69146c10192

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

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

</section>

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