Apply a plane rotation with real cosine and complex sine to a pair of single-precision complex floating-point vectors.
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 );