@stdlib/number-float64-base-from-words

Create a double-precision floating-point number from a higher order word and a lower order word.

Usage no npm install needed!

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README

From Words

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Create a double-precision floating-point number from a higher order word and a lower order word.

Installation

npm install @stdlib/number-float64-base-from-words

Usage

var fromWords = require( '@stdlib/number-float64-base-from-words' );

fromWords( high, low )

Creates a double-precision floating-point number from a higher order word (unsigned 32-bit integer) and a lower order word (unsigned 32-bit integer).

var v = fromWords( 1774486211, 2479577218 );
// returns 3.14e201

v = fromWords( 3221823995, 1413754136 );
// returns -3.141592653589793

v = fromWords( 0, 0 );
// returns 0.0

v = fromWords( 2147483648, 0 );
// returns -0.0

v = fromWords( 2146959360, 0 );
// returns NaN

v = fromWords( 2146435072, 0 );
// returns Infinity

v = fromWords( 4293918720, 0 );
// returns -Infinity

Notes

  • For more information regarding higher and lower order words, see to-words.

Examples

var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var MAX_UINT32 = require( '@stdlib/constants-uint32-max' );
var fromWords = require( '@stdlib/number-float64-base-from-words' );

var high;
var low;
var x;
var i;

for ( i = 0; i < 100; i++ ) {
    high = round( randu()*MAX_UINT32 );
    low = round( randu()*MAX_UINT32 );
    x = fromWords( high, low );
    console.log( 'higher: %d. lower: %d. float: %d.', high, low, x );
}

C APIs

Usage

#include "stdlib/number/float64/base/from_words.h"

stdlib_base_float64_from_words( high, low, *x )

Creates a double-precision floating-point number from a higher order word and a lower order word.

#include <stdint.h>

uint32_t high = 1074339512;
uint32_t low = 1374389535;

double x;
stdlib_base_float64_from_words( high, low, &x );

The function accepts the following arguments:

  • high: [in] uint32_t higher order word.
  • low: [in] uint32_t lower order word.
  • x: [out] double* destination for a double-precision floating-point number.
void stdlib_base_float64_from_words( const uint32_t high, const uint32_t low, double *x );

Examples

#include "stdlib/number/float64/base/from_words.h"
#include <stdint.h>
#include <stdio.h>

int main() {
    uint32_t high = 1074339512;
    uint32_t low[] = { 0, 10000, 1000000, 1374389535 };

    double x;
    int i;
    for ( i = 0; i < 4; i++ ) {
        stdlib_base_float64_from_words( high, low[ i ], &x );
        printf( "high: %u, low: %u => %lf\n", high, low[ i ], x );
    }
}

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

Copyright © 2016-2022. The Stdlib Authors.