cflipsign

Return a double-precision complex floating-point number with the same magnitude as z and the sign of y*z.

Usage

var cflipsign = require( '@stdlib/math/base/special/cflipsign' );

cflipsign( z, y )

Returns a double-precision complex floating-point number with the same magnitude as z and the sign of y*z.

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

var v = cflipsign( new Complex128( -4.2, 5.5 ), -1.0 );
// returns <Complex128>

var re = real( v );
// returns 4.2

var im = imag( v );
// returns -5.5

Examples

var uniform = require( '@stdlib/random/base/uniform' ).factory;
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var cflipsign = require( '@stdlib/math/base/special/cflipsign' );

var rand = uniform( -50.0, 50.0 );

var z;
var y;
var i;
for ( i = 0; i < 100; i++ ) {
    z = new Complex128( rand(), rand() );
    y = rand();
    console.log( 'cflipsign(%s, %d) = %s', z, y, cflipsign( z, y ) );
}

C APIs

Usage

#include "stdlib/math/base/special/cflipsign.h"

stdlib_base_cflipsign( z, y )

Returns a double-precision complex floating-point number with the same magnitude as z and the sign of y*z.

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

stdlib_complex128_t z = stdlib_complex128( 2.5, -1.5 );

stdlib_complex128_t out = stdlib_base_cflipsign( z, -1.0 );

double re = stdlib_complex128_real( out );
// returns -2.5

double im = stdlib_complex128_imag( out );
// returns 1.5

The function accepts the following arguments:

z: [in] stdlib_complex128_t input value.
y: [in] double number from which to derive the sign.

stdlib_complex128_t stdlib_base_cflipsign( const stdlib_complex128_t z, const double y );

Examples

#include "stdlib/math/base/special/cflipsign.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 re1;
    double im1;
    double re2;
    double im2;
    int i;
    for ( i = 0; i < 4; i++ ) {
        v = x[ i ];
        y = stdlib_base_cflipsign( v, -1.0 );
        stdlib_complex128_reim( v, &re1, &im1 );
        stdlib_complex128_reim( y, &re2, &im2 );
        printf( "cflipsign(%lf + %lfi, %lf) = %lf + %lfi\n", re1, im1, -1.0, re2, im2 );
}