Returns a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.
npm install math-float64-normalizeNormalize
===
[![NPM version][npm-image]][npm-url] [![Build Status][build-image]][build-url] [![Coverage Status][coverage-image]][coverage-url] [![Dependencies][dependencies-image]][dependencies-url]
> Returns a normal number y and exponent exp satisfying x = y * 2^exp.
`` bash`
$ npm install math-float64-normalize
` javascript`
var normalize = require( 'math-float64-normalize' );
#### normalize( x )
Returns a normal number y and exponent exp satisfying x = y * 2^exp.
` javascript`
var out = normalize( 3.14e-319 );
// returns [ 1.4141234400356668e-303, -52 ]
The first element of the returned array corresponds to y and the second to exp.
` javascript
var pow = require( 'math-power' );
var y = out[ 0 ];
var exp = out[ 1 ];
var bool = ( y*pow(2,exp) === 3.14e-319 );
// returns true
`
The function expects a finite, non-zero numeric value x. If x == 0,
` javascript`
var out = normalize( 0 );
// returns [ 0, 0 ];
If x is either positive or negative infinity or NaN,
` javascript
var pinf = require( 'const-pinf-float64' );
var ninf = require( 'const-ninf-float64' );
var out = normalize( pinf );
// returns [ pinf, 0 ]
out = normalize( ninf );
// returns [ ninf, 0 ]
out = normalize( NaN );
// returns [ NaN, 0 ]
`
` javascript
var round = require( 'math-round' );
var pow = require( 'math-power' );
var normalize = require( 'math-float64-normalize' );
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 = Math.random() * 10;
// Generate an exponent on the interval (-308,-324):
exp = -309 - round( Math.random()*14 );
// Create a subnormal number (~2.23e-308, ~4.94e-324):
x = frac * pow( 10, 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,v[1]) );
}
`
To run the example code from the top-level application directory,
` bash`
$ node ./examples/index.js
---
This repository uses [tape][tape] for unit tests. To run the tests, execute the following command in the top-level application directory:
` bash`
$ make test
All new feature development should have corresponding unit tests to validate correct functionality.
This repository uses [Istanbul][istanbul] as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:
` bash`
$ make test-cov
Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,
` bash`
$ make view-cov
This repository uses [Testling][testling] for browser testing. To run the tests in a (headless) local web browser, execute the following command in the top-level application directory:
` bash`
$ make test-browsers
To view the tests in a local web browser,
` bash``
$ make view-browser-tests
---
Copyright © 2016. The [Compute.io][compute-io] Authors.
[npm-image]: http://img.shields.io/npm/v/math-float64-normalize.svg
[npm-url]: https://npmjs.org/package/math-float64-normalize
[build-image]: http://img.shields.io/travis/math-io/float64-normalize/master.svg
[build-url]: https://travis-ci.org/math-io/float64-normalize
[coverage-image]: https://img.shields.io/codecov/c/github/math-io/float64-normalize/master.svg
[coverage-url]: https://codecov.io/github/math-io/float64-normalize?branch=master
[dependencies-image]: http://img.shields.io/david/math-io/float64-normalize.svg
[dependencies-url]: https://david-dm.org/math-io/float64-normalize
[dev-dependencies-image]: http://img.shields.io/david/dev/math-io/float64-normalize.svg
[dev-dependencies-url]: https://david-dm.org/dev/math-io/float64-normalize
[github-issues-image]: http://img.shields.io/github/issues/math-io/float64-normalize.svg
[github-issues-url]: https://github.com/math-io/float64-normalize/issues
[tape]: https://github.com/substack/tape
[istanbul]: https://github.com/gotwarlost/istanbul
[testling]: https://ci.testling.com
[compute-io]: https://github.com/compute-io/