About stdlib...
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.
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Multiply a single-precision floating-point number by an integer power of two.
npm install @stdlib/math-base-special-ldexpf
Alternatively,
- To load the package in a website via a
script
tag without installation and bundlers, use the ES Module available on theesm
branch (see README). - If you are using Deno, visit the
deno
branch (see README for usage intructions). - For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the
umd
branch (see README).
The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.
To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.
var ldexpf = require( '@stdlib/math-base-special-ldexpf' );
Multiplies a single-precision floating-point number by an integer power of two (i.e., x = frac * 2^exp
).
var x = ldexpf( 0.5, 3 ); // => 0.5 * 2^3 = 0.5 * 8
// returns 4.0
x = ldexpf( 4.0, -2 ); // => 4 * 2^(-2) = 4 * (1/4)
// returns 1.0
If frac
equals positive or negative zero, NaN
, or positive or negative infinity
, the function returns a value equal to frac
.
var x = ldexpf( 0.0, 20 );
// returns 0.0
x = ldexpf( -0.0, 39 );
// returns -0.0
x = ldexpf( NaN, -101 );
// returns NaN
x = ldexpf( Infinity, 11 );
// returns Infinity
x = ldexpf( -Infinity, -118 );
// returns -Infinity
- This function is the inverse of
frexpf
.
var linspace = require( '@stdlib/array-base-linspace' );
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var ldexpf = require( '@stdlib/math-base-special-ldexpf' );
var frac = linspace( 0.0, 100.0, 10 );
var exp = discreteUniform( 100, 0, 10 );
var i;
for ( i = 0; i < frac.length; i++ ) {
console.log( 'ldexpf(%d,%d) = %d', frac[ i ], exp[ i ], ldexpf( frac[ i ], exp[ i ] ) );
}
#include "stdlib/math/base/special/ldexpf.h"
Multiplies a single-precision floating-point number by an integer power of two (i.e., x = frac * 2^exp
).
float x = stdlib_base_ldexpf( 0.5f, 3 ); // => 0.5 * 2^3 = 0.5 * 8
// returns 4.0f
The function accepts the following arguments:
- frac:
[in] float
input value. - exp:
[in] int32_t
integer power of two.
float stdlib_base_ldexpf( const float frac, const int32_t exp );
#include "stdlib/math/base/special/ldexpf.h"
#include <stdint.h>
#include <stdio.h>
int main( void ) {
float y;
int i;
const float frac[] = { 0.5f, 5.0f, 0.0f, 3.5f, 7.9f };
const int32_t exp[] = { 3, -2, 20, 39, 14 };
for ( i = 0; i < 5; i++ ) {
y = stdlib_base_ldexpf( frac[ i ], exp[ i ] );
printf( "ldexpf(%f, %d) = %f\n", frac[ i ], exp[ i ], y );
}
}
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.
See LICENSE.
Copyright © 2016-2024. The Stdlib Authors.