@stdlib/number-float64-base-set-high-word
v0.2.2
Published
Set the more significant 32 bits of a double-precision floating-point number.
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Set High Word
Set the more significant 32 bits of a double-precision floating-point number.
Installation
npm install @stdlib/number-float64-base-set-high-word
Usage
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 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
.
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
Examples
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 APIs
Usage
#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.
#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.
void stdlib_base_float64_set_high_word( const uint32_t high, double *x );
Examples
#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 );
}
}
See Also
@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
: set the less significant 32 bits of a double-precision floating-point number.
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.