stdlib-js
<summary>
About stdlib...
</summary>
We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.
The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.
When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.
To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!
Set High Word
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
Set the more significant 32 bits of a [double-precision floating-point number][ieee754].
bash
npm install @stdlib/number-float64-base-set-high-word
javascript
var setHighWord = require( '@stdlib/number-float64-base-set-high-word' );
#### setHighWord( x, high )
Sets the more significant 32 bits (higher order word) of a [double-precision floating-point number][ieee754] x to a bit sequence represented by an unsigned 32-bit integer high. The returned double will have the same less significant 32 bits (lower order word) as x.
javascript
var high = 5 >>> 0; // => 0 00000000000 00000000000000000101
var y = setHighWord( 3.14e201, high ); // => 0 00000000000 0000000000000000010110010011110010110101100010000010
// returns 1.18350528745e-313
var PINF = require( '@stdlib/constants-float64-pinf' ); // => 0 11111111111 00000000000000000000 00000000000000000000000000000000
high = 1072693248 >>> 0; // => 0 01111111111 00000000000000000000
// Set the higher order bits of `+infinity` to return `1`:
y = setHighWord( PINF, high ); // => 0 01111111111 0000000000000000000000000000000000000000000000000000
// returns 1.0
javascript
var pow = require( '@stdlib/math-base-special-pow' );
var round = require( '@stdlib/math-base-special-round' );
var randu = require( '@stdlib/random-base-randu' );
var MAX_UINT32 = require( '@stdlib/constants-uint32-max' );
var setHighWord = require( '@stdlib/number-float64-base-set-high-word' );
var high;
var frac;
var exp;
var x;
var y;
var i;
// Generate a random double-precision floating-point number:
frac = randu() * 10.0;
exp = -round( randu() * 323.0 );
x = frac * pow( 10.0, exp );
// Replace the higher order word of `x` to generate new random numbers having the same lower order word...
for ( i = 0; i < 100; i++ ) {
high = round( randu()*MAX_UINT32 );
y = setHighWord( x, high );
console.log( 'x: %d. new high word: %d. y: %d.', x, high, y );
}
c
#include "stdlib/number/float64/base/set_high_word.h"
#### stdlib_base_float64_set_high_word( high, *x )
Sets the more significant 32 bits of a double-precision floating-point number.
c
#include <stdint.h>
uint32_t high = 1074339512;
double x = 0.0;
stdlib_base_float64_set_high_word( high, &x );
The function accepts the following arguments:
- high: [in] uint32_t higher order word.
- x: [in-out] double* reference to (and destination for) a double-precision floating-point number.
c
void stdlib_base_float64_set_high_word( const uint32_t high, double *x );
c
#include "stdlib/number/float64/base/set_high_word.h"
#include <stdint.h>
#include <stdio.h>
int main( void ) {
uint32_t high[] = { 1074339512, 1074339513, 1074339514, 1074339515 };
double x = 3.14;
int i;
for ( i = 0; i < 4; i++ ) {
stdlib_base_float64_set_high_word( high[ i ], &x );
printf( "high: %u => %lf\n", high[ i ], x );
}
}
@stdlib/number-float64/base/get-high-word][@stdlib/number/float64/base/get-high-word]: return an unsigned 32-bit integer corresponding to the more significant 32 bits of a double-precision floating-point number.
- [@stdlib/number-float64/base/set-low-word][@stdlib/number/float64/base/set-low-word]: set the less significant 32 bits of a double-precision floating-point number.
