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Scales a double-precision complex floating-point vector by a double-precision complex floating-point constant.
import zscal from 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-base-zscal@esm/index.mjs';
Scales values from zx
by za
.
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@esm/index.mjs';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@esm/index.mjs';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@esm/index.mjs';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@esm/index.mjs';
var zx = new Complex128Array( [ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 ] );
var za = new Complex128( 2.0, 0.0 );
zscal( 3, za, zx, 1 );
var z = zx.get( 0 );
// returns <Complex128>
var re = real( z );
// returns 2.0
var im = imag( z );
// returns 2.0
The function has the following parameters:
- N: number of indexed elements.
- za: scalar
Complex128
constant. - zx: input
Complex128Array
. - strideX: index increment for
zx
.
The N
and stride parameters determine how values from zx
are scaled by za
. For example, to scale every other value in zx
by za
,
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@esm/index.mjs';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@esm/index.mjs';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@esm/index.mjs';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@esm/index.mjs';
var zx = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var za = new Complex128( 2.0, 0.0 );
zscal( 2, za, zx, 2 );
var z = zx.get( 2 );
// returns <Complex128>
var re = real( z );
// returns 10.0
var im = imag( z );
// returns 12.0
Note that indexing is relative to the first index. To introduce an offset, use typed array
views.
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@esm/index.mjs';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@esm/index.mjs';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@esm/index.mjs';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@esm/index.mjs';
// Initial array:
var zx0 = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
// Define a scalar constant:
var za = new Complex128( 2.0, 2.0 );
// Create an offset view:
var zx1 = new Complex128Array( zx0.buffer, zx0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
// Scales every other value from `zx1` by `za`...
zscal( 3, za, zx1, 1 );
var z = zx0.get( 1 );
// returns <Complex128>
var re = real( z );
// returns -2.0
var im = imag( z );
// returns 14.0
Scales values from zx
by za
using alternative indexing semantics.
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@esm/index.mjs';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@esm/index.mjs';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@esm/index.mjs';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@esm/index.mjs';
var zx = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
var za = new Complex128( 2.0, 2.0 );
zscal.ndarray( 3, za, zx, 1, 0 );
var z = zx.get( 0 );
// returns <Complex128>
var re = real( z );
// returns -2.0
var im = imag( z );
// returns 6.0
The function has the following additional parameters:
- offsetX: starting index for
zx
.
While typed array
views mandate a view offset based on the underlying buffer, the offset parameter supports indexing semantics based on a starting index. For example, to scale every other value in the input strided array starting from the second element,
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@esm/index.mjs';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@esm/index.mjs';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@esm/index.mjs';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@esm/index.mjs';
var zx = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var za = new Complex128( 2.0, 2.0 );
zscal.ndarray( 2, za, zx, 2, 1 );
var z = zx.get( 3 );
// returns <Complex128>
var re = real( z );
// returns -2.0
var im = imag( z );
// returns 30.0
<!DOCTYPE html>
<html lang="en">
<body>
<script type="module">
import discreteUniform from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-discrete-uniform@esm/index.mjs';
import filledarrayBy from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-filled-by@esm/index.mjs';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@esm/index.mjs';
import zscal from 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-base-zscal@esm/index.mjs';
function rand() {
return new Complex128( discreteUniform( 0, 10 ), discreteUniform( -5, 5 ) );
}
var zx = filledarrayBy( 10, 'complex128', rand );
console.log( zx.toString() );
var za = new Complex128( 2.0, 2.0 );
console.log( za.toString() );
// Scales elements from `zx` by `za`:
zscal( zx.length, za, zx, 1 );
console.log( zx.get( zx.length-1 ).toString() );
</script>
</body>
</html>
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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.
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