@stdlib/blas-base-gcopy

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We greatly appreciate your continued support!</p> </details> # gcopy [![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]  > Copy values from `x` into `y`. <section class="installation"> ## Installation ```bash npm install @stdlib/blas-base-gcopy ``` </section> <section class="usage"> ## Usage ```javascript var gcopy = require( '@stdlib/blas-base-gcopy' ); ``` #### gcopy( N, x, strideX, y, strideY ) Copies values from `x` into `y`. ```javascript var x = [ 1.0, 2.0, 3.0, 4.0, 5.0 ]; var y = [ 6.0, 7.0, 8.0, 9.0, 10.0 ]; gcopy( x.length, x, 1, y, 1 ); // y => [ 1.0, 2.0, 3.0, 4.0, 5.0 ] ``` The function has the following parameters: - **N**: number of indexed elements. - **x**: input array. - **strideX**: index increment for `x`. - **y**: output array. - **strideY**: index increment for `y`. The `N` and stride parameters determine how values from `x` are copied into `y`. For example, to copy in reverse order every other value in `x` into the first `N` elements of `y`, ```javascript var x = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ]; var y = [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ]; gcopy( 3, x, -2, y, 1 ); // y => [ 5.0, 3.0, 1.0, 10.0, 11.0, 12.0 ] ``` Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views.  ```javascript var Float64Array = require( '@stdlib/array-float64' ); // Initial arrays... var x0 = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] ); var y0 = new Float64Array( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] ); // Create offset views... var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element var y1 = new Float64Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element // Copy in reverse order every other value from `x1` into `y1`... gcopy( 3, x1, -2, y1, 1 ); // y0 => <Float64Array>[ 7.0, 8.0, 9.0, 6.0, 4.0, 2.0 ] ``` #### gcopy.ndarray( N, x, strideX, offsetX, y, strideY, offsetY ) Copies values from `x` into `y` using alternative indexing semantics. ```javascript var x = [ 1.0, 2.0, 3.0, 4.0, 5.0 ]; var y = [ 6.0, 7.0, 8.0, 9.0, 10.0 ]; gcopy.ndarray( x.length, x, 1, 0, y, 1, 0 ); // y => [ 1.0, 2.0, 3.0, 4.0, 5.0 ] ``` The function has the following additional parameters: - **offsetX**: starting index for `x`. - **offsetY**: starting index for `y`. 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, to copy every other value in `x` starting from the second value into the last `N` elements in `y` where `x[i] = y[n]`, `x[i+2] = y[n-1]`,..., ```javascript var x = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ]; var y = [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ]; gcopy.ndarray( 3, x, 2, 1, y, -1, y.length-1 ); // y => [ 7.0, 8.0, 9.0, 6.0, 4.0, 2.0 ] ``` </section>  <section class="notes"> ## Notes - If `N <= 0`, both functions return `y` unchanged. - Both functions support array-like objects having getter and setter accessors for array element access (e.g., [`@stdlib/array-complex64`][@stdlib/array/complex64]). - `gcopy()` corresponds to the [BLAS][blas] level 1 function [`dcopy`][dcopy] with the exception that this implementation works with any array type, not just Float64Arrays. Depending on the environment, the typed versions ([`dcopy`][@stdlib/blas/base/dcopy], [`scopy`][@stdlib/blas/base/scopy], etc.) are likely to be significantly more performant. </section>  <section class="examples"> ## Examples  ```javascript var discreteUniform = require( '@stdlib/random-array-discrete-uniform' ); var gcopy = require( '@stdlib/blas-base-gcopy' ); var opts = { 'dtype': 'float64' }; var x = discreteUniform( 10, 0, 500, opts ); console.log( x ); var y = discreteUniform( x.length, 0, 255, opts ); console.log( y ); // Copy elements from `x` into `y` starting from the end of `y`: gcopy( x.length, x, 1, y, -1 ); console.log( y ); ``` </section>   <section class="related"> * * * ## See Also - <span class="package-name">[`@stdlib/blas-base/dcopy`][@stdlib/blas/base/dcopy]</span><span class="delimiter">: </span><span class="description">copy values from x into y.</span> - <span class="package-name">[`@stdlib/blas-base/scopy`][@stdlib/blas/base/scopy]</span><span class="delimiter">: </span><span class="description">copy values from x into y.</span> </section>   <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 © 2016-2024. The Stdlib [Authors][stdlib-authors]. </section>   <section class="links"> [npm-image]: http://img.shields.io/npm/v/@stdlib/blas-base-gcopy.svg [npm-url]: https://npmjs.org/package/@stdlib/blas-base-gcopy [test-image]: https://github.com/stdlib-js/blas-base-gcopy/actions/workflows/test.yml/badge.svg?branch=v0.2.1 [test-url]: https://github.com/stdlib-js/blas-base-gcopy/actions/workflows/test.yml?query=branch:v0.2.1 [coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/blas-base-gcopy/main.svg [coverage-url]: https://codecov.io/github/stdlib-js/blas-base-gcopy?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/blas-base-gcopy/tree/deno [deno-readme]: https://github.com/stdlib-js/blas-base-gcopy/blob/deno/README.md [umd-url]: https://github.com/stdlib-js/blas-base-gcopy/tree/umd [umd-readme]: https://github.com/stdlib-js/blas-base-gcopy/blob/umd/README.md [esm-url]: https://github.com/stdlib-js/blas-base-gcopy/tree/esm [esm-readme]: https://github.com/stdlib-js/blas-base-gcopy/blob/esm/README.md [branches-url]: https://github.com/stdlib-js/blas-base-gcopy/blob/main/branches.md [stdlib-license]: https://raw.githubusercontent.com/stdlib-js/blas-base-gcopy/main/LICENSE [blas]: http://www.netlib.org/blas [dcopy]: http://www.netlib.org/lapack/explore-html/de/da4/group__double__blas__level1.html [mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray [@stdlib/array/complex64]: https://www.npmjs.com/package/@stdlib/array-complex64 [@stdlib/blas/base/dcopy]: https://www.npmjs.com/package/@stdlib/blas-base-dcopy [@stdlib/blas/base/scopy]: https://www.npmjs.com/package/@stdlib/blas-base-scopy   </section>