time-to-botec/js/node_modules/@stdlib/math/base/special/cflipsign/README.md

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# Flipsign

> Return a complex number with the same magnitude as `z` and the sign of `y*z`.

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## Usage

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

#### cflipsign( \[out,] re, im, y )

Returns a complex number with the same magnitude as `z` and the sign of `y*z`.

```javascript
var v = cflipsign( -4.2, 5.5, -4 );
// returns [ 4.2, -5.5 ]

v = cflipsign( 0.0, 0.0, 5 );
// returns [ 0.0, 0.0 ]

v = cflipsign( NaN, NaN, 6 );
// returns [ NaN, NaN ]
```

By default, the function returns real and imaginary components as a two-element `array`. To avoid unnecessary memory allocation, the function supports providing an output (destination) object.

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

var out = new Float64Array( 2 );

var v = cflipsign( out, -4.2, 5.5, 77 );
// returns <Float64Array>[ -4.2, 5.5 ]

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

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## Examples

<!-- eslint no-undef: "error" -->

```javascript
var Complex128 = require( '@stdlib/complex/float64' );
var randu = require( '@stdlib/random/base/randu' );
var real = require( '@stdlib/complex/real' );
var imag = require( '@stdlib/complex/imag' );
var cflipsign = require( '@stdlib/math/base/special/cflipsign' );

var re;
var im;
var z;
var o;
var w;
var i;
var y;

for ( i = 0; i < 100; i++ ) {
    re = ( randu()*100.0 ) - 50.0;
    im = ( randu()*100.0 ) - 50.0;
    y = ( randu()*100.0 ) - 50.0;
    z = new Complex128( re, im );
    o = cflipsign( real(z), imag(z), y );
    w = new Complex128( o[ 0 ], o[ 1 ] );
    console.log( 'flipsign(%s) = %s', z.toString(), w.toString() );
}
```

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