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Apply a plane rotation with real cosine and complex sine to a pair of single-precision complex floating-point vectors.
npm install @stdlib/lapack-base-crotAlternatively,
- To load the package in a website via a
scripttag without installation and bundlers, use the ES Module available on theesmbranch (see README). - If you are using Deno, visit the
denobranch (see README for usage intructions). - For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the
umdbranch (see README).
The branches.md 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.
var crot = require( '@stdlib/lapack-base-crot' );Applies a plane rotation with real cosine and complex sine.
var Complex64Array = require( '@stdlib/array-complex64' );
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var realf = require( '@stdlib/complex-float32-real' );
var imagf = require( '@stdlib/complex-float32-imag' );
var cx = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var cy = new Complex64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
var s = new Complex64( 0.0, 0.75 );
crot( cx.length, cx, 1, cy, 1, 1.25, s );
var z = cy.get( 0 );
// returns <Complex64>
var re = realf( z );
// returns ~-1.5
var im = imagf( z );
// returns ~0.75
z = cx.get( 0 );
// returns <Complex64>
re = realf( z );
// returns ~1.25
im = imagf( z );
// returns ~2.5The function has the following parameters:
- N: number of indexed elements.
- cx: first input
Complex64Array. - strideCX: stride length for
cx. - cy: second input
Complex64Array. - strideCY: stride length for
cy.
The N and stride parameters determine how values from cx and cy are accessed at runtime. For example, to apply a plane rotation to every other element,
var Complex64Array = require( '@stdlib/array-complex64' );
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var realf = require( '@stdlib/complex-float32-real' );
var imagf = require( '@stdlib/complex-float32-imag' );
var cx = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var cy = new Complex64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
var s = new Complex64( 0.0, 0.75 );
crot( 2, cx, 2, cy, 2, 1.25, s );
var z = cy.get( 0 );
// returns <Complex64>
var re = realf( z );
// returns ~-1.5
var im = imagf( z );
// returns ~0.75
z = cx.get( 0 );
// returns <Complex64>
re = realf( z );
// returns ~1.25
im = imagf( z );
// returns ~2.5Note that indexing is relative to the first index. To introduce an offset, use typed array views.
var Complex64Array = require( '@stdlib/array-complex64' );
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var realf = require( '@stdlib/complex-float32-real' );
var imagf = require( '@stdlib/complex-float32-imag' );
// Initial arrays...
var cx0 = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var cy0 = new Complex64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
// Create offset views...
var cx1 = new Complex64Array( cx0.buffer, cx0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var cy1 = new Complex64Array( cy0.buffer, cy0.BYTES_PER_ELEMENT*2 ); // start at 3rd element
var s = new Complex64( 0.0, 0.75 );
crot( 2, cx1, -2, cy1, 1, 1.25, s );
var z = cy0.get( 2 );
// returns <Complex64>
var re = realf( z );
// returns ~-6
var im = imagf( z );
// returns ~5.25
z = cx0.get( 3 );
// returns <Complex64>
re = realf( z );
// returns ~8.75
im = imagf( z );
// returns ~10Applies a plane rotation with real cosine and complex sine using alternative indexing semantics.
var Complex64Array = require( '@stdlib/array-complex64' );
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var realf = require( '@stdlib/complex-float32-real' );
var imagf = require( '@stdlib/complex-float32-imag' );
var cx = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
var cy = new Complex64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
var s = new Complex64( 0.0, 0.75 );
crot.ndarray( cx.length, cx, 1, 0, cy, 1, 0, 1.25, s );
var z = cy.get( 0 );
// returns <Complex64>
var re = realf( z );
// returns ~-1.5
var im = imagf( z );
// returns ~0.75
z = cx.get( 0 );
// returns <Complex64>
re = realf( z );
// returns ~1.25
im = imagf( z );
// returns ~2.5The function has the following additional parameters:
- offsetCX: starting index for
cx. - offsetCY: starting index for
cy.
While 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 apply a plane rotation to every other element starting from the second element,
var Complex64Array = require( '@stdlib/array-complex64' );
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var realf = require( '@stdlib/complex-float32-real' );
var imagf = require( '@stdlib/complex-float32-imag' );
var cx = new Complex64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var cy = new Complex64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
var s = new Complex64( 0.0, 0.75 );
crot.ndarray( 2, cx, 2, 1, cy, 2, 1, 1.25, s );
var z = cy.get( 3 );
// returns <Complex64>
var re = realf( z );
// returns ~-6.0
var im = imagf( z );
// returns ~5.25
z = cx.get( 1 );
// returns <Complex64>
re = realf( z );
// returns ~3.75
im = imagf( z );
// returns ~5.0var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var filledarrayBy = require( '@stdlib/array-filled-by' );
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var ccopy = require( '@stdlib/blas-base-ccopy' );
var zeros = require( '@stdlib/array-zeros' );
var logEach = require( '@stdlib/console-log-each' );
var crot = require( '@stdlib/lapack-base-crot' );
function rand() {
return new Complex64( discreteUniform( 0, 10 ), discreteUniform( -5, 5 ) );
}
// Generate random input arrays:
var cx = filledarrayBy( 10, 'complex64', rand );
var cxc = ccopy( cx.length, cx, 1, zeros( cx.length, 'complex64' ), 1 );
var cy = filledarrayBy( 10, 'complex64', rand );
var cyc = ccopy( cy.length, cy, 1, zeros( cy.length, 'complex64' ), 1 );
var s = new Complex64( 0.0, 0.75 );
// Apply a plane rotation:
crot( cx.length, cx, 1, cy, 1, 1.25, s );
// Print the results:
logEach( '(%s,%s) => (%s,%s)', cxc, cyc, cx, cy );This package is part of 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, see the main project repository.
See LICENSE.
Copyright © 2016-2025. The Stdlib Authors.