@stdlib/complex-float64-base-scale

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scale

Scale a double-precision complex floating-point number by a real-valued double-precision floating-point scalar constant.

Installation

npm install @stdlib/complex-float64-base-scale

Usage

var scale = require( '@stdlib/complex-float64-base-scale' );

scale( alpha, z )

Scales a double-precision complex floating-point number by a real-valued double-precision floating-point scalar constant.

var Complex128 = require( '@stdlib/complex-float64-ctor' );

var z = new Complex128( 5.0, 3.0 );

var v = scale( 5.0, z );
// returns <Complex128>[ 25.0, 15.0 ]

The function supports the following parameters:

• alpha: real-valued scalar constant.
• z: complex number.

scale.assign( alpha, re1, im1, out, strideOut, offsetOut )

Scales a double-precision complex floating-point number by a real-valued double-precision floating-point scalar constant and assigns results to a provided output array.

var Float64Array = require( '@stdlib/array-float64' );

var out = new Float64Array( 2 );
var v = scale.assign( 5.0, 5.0, 3.0, out, 1, 0 );
// returns <Float64Array>[ 25.0, 15.0 ]

var bool = ( out === v );
// returns true

The function supports the following parameters:

• alpha: real-valued scalar constant.
• re: real component of the complex number.
• im: imaginary component of the complex number.
• out: output array.
• strideOut: stride length for out.
• offsetOut: starting index for out.

scale.strided( alpha, z, sz, oz, out, so, oo )

Scales a double-precision complex floating-point number stored in a real-valued strided array view by a real-valued double-precision floating-point scalar constant and assigns results to a provided strided output array.

var Float64Array = require( '@stdlib/array-float64' );

var z = new Float64Array( [ 5.0, 3.0 ] );
var out = new Float64Array( 2 );

var v = scale.strided( 5.0, z, 1, 0, out, 1, 0 );
// returns <Float64Array>[ 25.0, 15.0 ]

var bool = ( out === v );
// returns true

The function supports the following parameters:

• alpha: real-valued scalar constant.
• z: complex number strided array view.
• sz: stride length for z.
• oz: starting index for z.
• out: output array.
• so: stride length for out.
• oo: starting index for out.

Examples

var Complex128Array = require( '@stdlib/array-complex128' );
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var scale = require( '@stdlib/complex-float64-base-scale' );

// Generate an array of random values:
var values = new Complex128Array( discreteUniform( 200, -50, 50 ) );

// Scale each by a scalar constant:
logEachMap( '%0.1f * (%s) = %s', 5.0, values, scale );

C APIs

Usage

#include "stdlib/complex/float64/base/scale.h"

stdlib_base_complex128_scale( alpha, z )

Scales a double-precision complex floating-point number by a real-valued double-precision floating-point scalar constant.

#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/real.h"
#include "stdlib/complex/float64/imag.h"

stdlib_complex128_t z = stdlib_complex128( 5.0, 3.0 );

stdlib_complex128_t out = stdlib_base_complex128_scale( 5.0, z );

double re = stdlib_complex128_real( out );
// returns 25.0

double im = stdlib_complex128_imag( out );
// returns 15.0

The function accepts the following arguments:

• alpha: [in] double scalar constant.
• z: [in] stdlib_complex128_t complex number.

stdlib_complex128_t stdlib_base_complex128_scale( const double alpha, const stdlib_complex128_t z );

Examples

#include "stdlib/complex/float64/base/scale.h"
#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/reim.h"
#include <stdio.h>

int main( void ) {
    const stdlib_complex128_t x[] = {
        stdlib_complex128( 3.14, 1.5 ),
        stdlib_complex128( -3.14, 1.5 ),
        stdlib_complex128( 0.0, -0.0 ),
        stdlib_complex128( 0.0/0.0, 0.0/0.0 )
    };

    stdlib_complex128_t v;
    stdlib_complex128_t y;
    double re;
    double im;
    int i;
    for ( i = 0; i < 4; i++ ) {
        v = x[ i ];
        stdlib_complex128_reim( v, &re, &im );
        printf( "z = %lf + %lfi\n", re, im );

        y = stdlib_base_complex128_scale( 5.0, v );
        stdlib_complex128_reim( y, &re, &im );
        printf( "scale(5.0, z) = %lf + %lfi\n", re, im );
    }
}

Notice

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.

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License

See LICENSE.

Copyright

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