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# npm

## @stdlib/math-base-special-flipsignf 0.0.1 • Public • Published

# flipsignf

Return a single-precision floating-point number with the magnitude of `x` and the sign of `x*y`.

## Installation

`npm install @stdlib/math-base-special-flipsignf`

## Usage

`var flipsignf = require( '@stdlib/math-base-special-flipsignf' );`

#### flipsignf( x, y )

Returns a single-precision floating-point number with the magnitude of `x` and the sign of `x*y` (i.e., only return `-x` when `y` is a negative number).

```var z = flipsignf( -3.0, 10.0 );
// returns -3.0

z = flipsignf( -3.0, -1.0 );
// returns 3.0

z = flipsignf( 1.0, -0.0 );
// returns -1.0

z = flipsignf( -3.0, -0.0 );
// returns 3.0

z = flipsignf( -0.0, 1.0 );
// returns -0.0

z = flipsignf( 0.0, -1.0 );
// returns -0.0```

## Notes

• According to the IEEE 754 standard, a `NaN` has a biased exponent equal to `255`, a significand greater than `0`, and a sign bit equal to either `1` or `0`. In which case, `NaN` may not correspond to just one but many binary representations. Accordingly, care should be taken to ensure that `y` is not `NaN`; otherwise, behavior may be indeterminate.

## Examples

```var randu = require( '@stdlib/random-base-randu' );
var flipsignf = require( '@stdlib/math-base-special-flipsignf' );

var x;
var y;
var z;
var i;

// Generate random numbers `x` and `y` and flip the sign of `x` only if `y` is negative...
for ( i = 0; i < 100; i++ ) {
x = (randu()*100.0) - 50.0;
y = (randu()*10.0) - 5.0;
z = flipsignf( x, y );
console.log( 'x: %d, y: %d => %d', x, y, z );
}```

## C APIs

### Usage

`#include "stdlib/math/base/special/flipsignf.h"`

#### stdlib_base_flipsignf( x, y )

Returns a single-precision floating-point number with the magnitude of `x` and the sign of `x*y`.

```float v = stdlib_base_flipsignf( -3.0f, 10.0f );
// returns -3.0f

float v = stdlib_base_flipsignf( -3.0f, -1.0f );
// returns 3.0f```

The function accepts the following arguments:

• x: `[in] float` number from which to derive a magnitude.
• y: `[in] float` number from which to derive a sign.
`float stdlib_base_flipsignf( const float x, const float y );`

### Examples

```#include "stdlib/math/base/special/flipsignf.h"
#include <stdio.h>

int main() {
float x[] = { 3.0f, -3.0f, 0.0f, 0.0f/0.0f };

float y;
int i;
for ( i = 0; i < 4; i++ ) {
y = stdlib_base_flipsignf( x[ i ], -3.0f );
printf( "flipsignf(%f, %f) = %f\n", x[ i ], -3.0f, y );
}
}```

## 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.

#### Community ### Install

`npm i @stdlib/math-base-special-flipsignf`

stdlib.io

31

0.0.1