Copy values from x into y.
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> Copy values from x into y.
``bash`
npm install @stdlib/blas-base-scopy
`javascript`
var scopy = require( '@stdlib/blas-base-scopy' );
#### scopy( N, x, strideX, y, strideY )
Copies values from x into y.
`javascript
var Float32Array = require( '@stdlib/array-float32' );
var x = new Float32Array( [ 1.0, 2.0, 3.0, 4.0, 5.0 ] );
var y = new Float32Array( [ 6.0, 7.0, 8.0, 9.0, 10.0 ] );
scopy( x.length, x, 1, y, 1 );
// y =>
`
The function has the following parameters:
- N: number of indexed elements.
- x: input [Float32Array][mdn-float32array].x
- strideX: index increment for .Float32Array
- y: output [][mdn-float32array].y
- strideY: index increment for .
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 Float32Array = require( '@stdlib/array-float32' );
var x = new Float32Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
var y = new Float32Array( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
scopy( 3, x, -2, y, 1 );
// y =>
`
Note that indexing is relative to the first index. To introduce an offset, use [typed array][mdn-typed-array] views.
`javascript
var Float32Array = require( '@stdlib/array-float32' );
// Initial arrays...
var x0 = new Float32Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
var y0 = new Float32Array( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
// Create offset views...
var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var y1 = new Float32Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element
// Copy in reverse order every other value from x1 into y1...`
scopy( 3, x1, -2, y1, 1 );
// y0 =>
#### scopy.ndarray( N, x, strideX, offsetX, y, strideY, offsetY )
Copies values from x into y using alternative indexing semantics.
`javascript
var Float32Array = require( '@stdlib/array-float32' );
var x = new Float32Array( [ 1.0, 2.0, 3.0, 4.0, 5.0 ] );
var y = new Float32Array( [ 6.0, 7.0, 8.0, 9.0, 10.0 ] );
scopy.ndarray( x.length, x, 1, 0, y, 1, 0 );
// y =>
`
The function has the following additional parameters:
- offsetX: starting index for x.y
- offsetY: starting index for .
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 Float32Array = require( '@stdlib/array-float32' );
var x = new Float32Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
var y = new Float32Array( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
scopy.ndarray( 3, x, 2, 1, y, -1, y.length-1 );
// y =>
`
- If N <= 0, both functions return y unchanged.scopy()
- corresponds to the [BLAS][blas] level 1 function [scopy][scopy].
`javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var scopy = require( '@stdlib/blas-base-scopy' );
var opts = {
'dtype': 'float32'
};
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:`
scopy( x.length, x, 1, y, -1 );
console.log( y );
*
`c`
#include "stdlib/blas/base/scopy.h"
#### c_scopy( N, \X, strideX, \Y, strideY )
Copies values from X into Y.
`c
const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f };
float y[] = { 0.0f, 0.0f, 0.0f, 0.0f };
c_scopy( 4, x, 1, y, 1 );
`
The function accepts the following arguments:
- N: [in] CBLAS_INT number of indexed elements.[in] float*
- X: input array.[in] CBLAS_INT
- strideX: index increment for X.[out] float*
- Y: output array.[in] CBLAS_INT
- strideY: index increment for Y.
`c`
void c_scopy( const CBLAS_INT N, const float X, const CBLAS_INT strideX, float Y, const CBLAS_INT strideY );
#### c_scopy_ndarray( N, \X, strideX, offsetX, \Y, strideY, offsetY )
Copies values from x into y using alternative indexing semantics.
`c
const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f };
float y[] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
c_scopy_ndarray( 3, x, 1, 2, y, 1, 2 );
`
The function accepts the following arguments:
- N: [in] CBLAS_INT number of indexed elements.[in] float*
- X: input array.[in] CBLAS_INT
- strideX: index increment for X.[in] CBLAS_INT
- offsetX: starting index for X.[out] float*
- Y: output array.[in] CBLAS_INT
- strideY: index increment for Y.[in] CBLAS_INT
- offsetY: starting index for Y.
`c`
void c_scopy_ndarray( const CBLAS_INT N, const float X, const CBLAS_INT strideX, const CBLAS_INT offsetX, float Y, const CBLAS_INT strideY, const CBLAS_INT offsetY );
`c
#include "stdlib/blas/base/scopy.h"
#include
int main( void ) {
// Create strided arrays:
const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f };
float y[] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
// Specify the number of elements:
const int N = 4;
// Specify stride lengths:
const int strideX = 2;
const int strideY = -2;
// Copy elements:
c_scopy( N, x, strideX, y, strideY );
// Print the result:
for ( int i = 0; i < 8; i++ ) {
printf( "y[ %i ] = %f\n", i, y[ i ] );
}
// Copy elements:
c_scopy_ndarray( N, x, strideX, 0, y, strideY, 6 );
// Print the result:
for ( int i = 0; i < 8; i++ ) {
printf( "y[ %i ] = %f\n", i, y[ i ] );
}
}
`
*
- [@stdlib/blas-base/dcopy][@stdlib/blas/base/dcopy]: copy values from x into y.
- [@stdlib/blas-base/gcopy][@stdlib/blas/base/gcopy]: copy values from x into y.
- [@stdlib/blas-base/sswap][@stdlib/blas/base/sswap]: interchange two single-precision floating-point vectors.
*
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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---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[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-scopy/tree/deno
[deno-readme]: https://github.com/stdlib-js/blas-base-scopy/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/blas-base-scopy/tree/umd
[umd-readme]: https://github.com/stdlib-js/blas-base-scopy/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/blas-base-scopy/tree/esm
[esm-readme]: https://github.com/stdlib-js/blas-base-scopy/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/blas-base-scopy/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/blas-base-scopy/main/LICENSE
[blas]: http://www.netlib.org/blas
[scopy]: http://www.netlib.org/lapack/explore-html/df/d28/group__single__blas__level1.html
[mdn-float32array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float32Array
[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
[@stdlib/blas/base/dcopy]: https://www.npmjs.com/package/@stdlib/blas-base-dcopy
[@stdlib/blas/base/gcopy]: https://www.npmjs.com/package/@stdlib/blas-base-gcopy
[@stdlib/blas/base/sswap]: https://www.npmjs.com/package/@stdlib/blas-base-sswap