Skip to content

Latest commit

 

History

History
280 lines (177 loc) · 8.71 KB

README.md

File metadata and controls

280 lines (177 loc) · 8.71 KB
Raw
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!

normalize

NPM version Build Status Coverage Status

Return a normal number y and exponent exp satisfying x = y * 2^exp.

Usage

To use in Observable,

normalize = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/number-float64-base-normalize@umd/browser.js' )

To vendor stdlib functionality and avoid installing dependency trees for Node.js, you can use the UMD server build:

var normalize = require( 'path/to/vendor/umd/number-float64-base-normalize/index.js' )

To include the bundle in a webpage,

<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/number-float64-base-normalize@umd/browser.js"></script>

If no recognized module system is present, access bundle contents via the global scope:

<script type="text/javascript">
(function () {
    window.normalize;
})();
</script>

normalize( x )

Returns a normal number y and exponent exp satisfying x = y * 2^exp.

var pow = require( '@stdlib/math-base-special-pow' );

var out = normalize( 3.14e-319 );
// returns [ 1.4141234400356668e-303, -52 ]

var y = out[ 0 ];
var exp = out[ 1 ];

var bool = ( y*pow(2.0, exp) === 3.14e-319 );
// returns true

The function expects a finite, non-zero numeric value x. If x == 0,

var out = normalize( 0.0 );
// returns [ 0.0, 0 ];

If x is either positive or negative infinity or NaN,

var PINF = require( '@stdlib/constants-float64-pinf' );
var NINF = require( '@stdlib/constants-float64-ninf' );

var out = normalize( PINF );
// returns [ Infinity, 0 ]

out = normalize( NINF );
// returns [ -Infinity, 0 ]

out = normalize( NaN );
// returns [ NaN, 0 ]

normalize.assign( x, out, stride, offset )

Returns a normal number y and exponent exp satisfying x = y * 2^exp and assigns results to a provided output array.

var Float64Array = require( '@stdlib/array-float64' );

var out = new Float64Array( 2 );

var v = normalize.assign( 3.14e-319, out, 1, 0);
// returns <Float64Array>[ 1.4141234400356668e-303, -52 ]

var bool = ( v === out );
// returns true

Examples

<!DOCTYPE html>
<html lang="en">
<body>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-base-discrete-uniform@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-base-uniform@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-pow@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/number-float64-base-normalize@umd/browser.js"></script>
<script type="text/javascript">
(function () {

var frac;
var exp;
var x;
var v;
var i;

// Generate denormalized numbers and then normalize them...
for ( i = 0; i < 100; i++ ) {
    // Generate a random fraction:
    frac = randu( 0.0, 10.0 );

    // Generate an exponent on the interval (-308,-324):
    exp = discreteUniform( -323, -309 );

    // Create a subnormal number (~2.23e-308, ~4.94e-324):
    x = frac * pow( 10.0, exp );

    // Determine a `y` and an `exp` to "normalize" the subnormal:
    v = normalize( x );

    console.log( '%d = %d * 2^%d = %d', x, v[0], v[1], v[0]*pow(2.0, v[1]) );
}

})();
</script>
</body>
</html>

See Also

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

Chat

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.