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

What is @stdlib/number-float64-base-from-words?

@stdlib/number-float64-base-from-words is a utility package that allows you to create a double-precision floating-point number from higher and lower order words (32-bit integers). This can be useful in low-level programming tasks, such as manipulating the binary representation of floating-point numbers.

What are @stdlib/number-float64-base-from-words's main functionalities?

Create a double-precision floating-point number from words

This feature allows you to create a double-precision floating-point number by specifying the higher and lower order words. In this example, the high word is 1074266112 and the low word is 0, which combine to form the number 3.14.

const fromWords = require('@stdlib/number-float64-base-from-words');
const high = 1074266112;
const low = 0;
const num = fromWords(high, low);
console.log(num); // 3.14

Other packages similar to @stdlib/number-float64-base-from-words

ieee754

The 'ieee754' package provides functions for encoding and decoding IEEE 754 floating-point numbers. It allows you to convert between binary representations and JavaScript numbers, similar to @stdlib/number-float64-base-from-words, but with a broader focus on IEEE 754 standards.

README

From Words

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 );
}

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C APIs

Installation

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

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 );
    }
}

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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 © 2016-2021. The Stdlib Authors.

Changelog

0.0.1 (2021-06-15)

No changes reported for this release.

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