modf

Decompose a double-precision floating-point number into integral and fractional parts.

Installation

npm install @stdlib/math-base-special-modf

Usage

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

modf( x )

Decomposes a double-precision floating-point number into integral and fractional parts, each having the same type and sign as x.

var parts = modf( 3.14 );
// returns [ 3.0, 0.14000000000000012 ]

parts = modf( +0.0 );
// returns [ +0.0, +0.0 ]

parts = modf( -0.0 );
// returns [ -0.0, -0.0 ]

parts = modf( Infinity );
// returns [ Infinity, +0.0 ]

parts = modf( -Infinity );
// returns [ -Infinity, -0.0 ]

parts = modf( NaN );
// returns [ NaN, NaN ]

modf.assign( x, out, stride, offset )

Decomposes a double-precision floating-point number into integral and fractional parts, each having the same type and sign as x, and assigns results to a provided output array.

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

var out = new Float64Array( 2 );

var parts = modf.assign( 3.14, out, 1, 0 );
// returns <Float64Array>[ 3.0, 0.14000000000000012 ]

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

Examples

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

var parts;
var x;
var i;

for ( i = 0; i < 100; i++ ) {
    x = (randu()*1000.0) - 500.0;
    parts = modf( x );
    console.log( 'modf(%d) => integral: %d. fraction: %d.', x, parts[ 0 ], parts[ 1 ] );
}

C APIs

Usage

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

stdlib_base_modf( x, integral, frac )

Decomposes a double-precision floating-point number into integral and fractional parts, each having the same type and sign as x.

double integral;
double frac;

stdlib_base_modf( 4.0, &integral, &frac );

The function accepts the following arguments:

• x: [in] double input value.
• frac: [out] double* destination for the integral part.
• exp: [out] double* destination for the fractional part.

void stdlib_base_modf( const double x, double *integral, double *frac );

Examples

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

int main( void ) {
    const double x[] = { 4.0, 0.0, -0.0, 1.0, -1.0, 3.14, -3.14, 1.0e308, -1.0e308, 1.0/0.0, -1.0/0.0, 0.0/0.0 };

    double integral;
    double frac;
    int i;
    for ( i = 0; i < 12; i++ ) {
        stdlib_base_modf( x[ i ], &integral, &frac );
        printf( "x: %lf => integral: %lf, frac: %lf\n", x[ i ], integral, frac );
    }
}

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

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.