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.

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!

toFloat64

Convert a half-precision floating-point number to the nearest double-precision floating-point number.

Installation

npm install @stdlib/number-float16-base-to-float64

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm 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.

Usage

var float16ToFloat64 = require( '@stdlib/number-float16-base-to-float64' );

float16ToFloat64( x )

Converts a half-precision floating-point number to the nearest double-precision floating-point number.

var float64ToFloat16 = require( '@stdlib/number-float64-base-to-float16' );

var y = float16ToFloat64( float64ToFloat16( 1.337 ) );
// returns 1.3369140625

Examples

var float64ToFloat16 = require( '@stdlib/number-float64-base-to-float16' );
var uniform = require( '@stdlib/random-array-uniform' );
var map = require( '@stdlib/array-base-map' );
var naryFunction = require( '@stdlib/utils-nary-function' );
var pickArguments = require( '@stdlib/utils-pick-arguments' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var float16ToFloat64 = require( '@stdlib/number-float16-base-to-float64' );

// Generate an array of random numbers:
var f64 = uniform( 100, 0.0, 100.0 );

// Convert each value to a half-precision floating-point number:
var f16 = map( f64, naryFunction( float64ToFloat16, 1 ) );

// Convert each half-precision floating-point number to the nearest double-precision floating-point number:
logEachMap( 'float64: %f => float16: %f => float64: %f', f64, f16, pickArguments( float16ToFloat64, [ 1 ] ) );

---

C APIs

Usage

#include "stdlib/number/float16/base/to_float64.h"

stdlib_base_float16_to_float64( x )

Converts a half-precision floating-point number to the nearest double-precision floating-point number.

#include "stdlib/number/float16/ctor.h"

stdlib_float16_t v = stdlib_float16_from_bits( 51648 ); // => -11.5
double x = stdlib_base_float16_to_float64( v );

The function accepts the following arguments:

• x: [in] stdlib_float16_t half-precision floating-point number.

double stdlib_base_float16_to_float64( const stdlib_float16_t x );

Examples

#include "stdlib/number/float16/base/to_float64.h"
#include "stdlib/number/float16/ctor.h"
#include <stdint.h>
#include <stdio.h>

int main( void ) {
    const stdlib_float16_t x[] = {
        stdlib_float16_from_bits( 51648 ), // -11.5
        stdlib_float16_from_bits( 18880 )  // 11.5
    };

    double v;
    int i;
    for ( i = 0; i < 2; i++ ) {
        v = stdlib_base_float16_to_float64( x[ i ] );
        printf( "float16 bits: %u => float64: %lf\n", stdlib_float16_to_bits( x[ i ] ), v );
    }
}

---

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 © 2016-2025. The Stdlib Authors.