Exponent

!NPM versionnpm-imagenpm-url !Build Statusbuild-imagebuild-url !Coverage Statuscoverage-imagecoverage-url !Dependenciesdependencies-imagedependencies-urlReturns an integer corresponding to the unbiased exponent of a double-precision floating-point numberieee754.

## Installation

`$ npm install math-float64-exponent`

## Usage

`var exponent = require( 'math-float64-exponent' );`

#### exponent( x )

Returns an`integer`

corresponding to the unbiased exponent of a double-precision floating-point numberieee754.```
var exp = exponent( 3.14e307 );
// returns 1021 => 2**1021 ~ 1e307
var exp = exponent( 3.14e-307 );
// returns -1019 => 2**-1019 ~ 1e-307
exp = exponent( -3.14 );
// returns 1
exp = exponent( 0 );
// returns 0
exp = exponent( NaN );
// returns 1024 => 2**1024 ~ infinity
```

## Examples

```
var round = require( 'math-round' );
var pow = require( 'math-power' );
var exponent = require( 'math-float64-exponent' );
var frac;
var exp;
var x;
var e;
var i;
// Generate random numbers and extract their exponents...
for ( i = 0; i < 100; i++ ) {
frac = Math.random() * 10;
exp = round( Math.random()*646 ) - 323;
x = frac * pow( 10, exp );
e = exponent( x );
console.log( 'x: %d. unbiased exponent: %d.', x, e );
}
```

To run the example code from the top-level application directory,

`$ node ./examples/index.js`

## Tests

### Unit

This repository uses tapetape for unit tests. To run the tests, execute the following command in the top-level application directory:`$ make test`

All new feature development should have corresponding unit tests to validate correct functionality.

### Test Coverage

This repository uses Istanbulistanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:`$ make test-cov`

Istanbul creates a

`./reports/coverage`

directory. To access an HTML version of the report,`$ make view-cov`

### Browser Support

This repository uses Testlingtestling for browser testing. To run the tests in a (headless) local web browser, execute the following command in the top-level application directory:`$ make test-browsers`

To view the tests in a local web browser,

`$ make view-browser-tests`