log1p

Computes the natural logarithm of 1+x.

Installation

$ npm install math-float64-log1p

Usage

var log1p = require( 'math-float64-log1p' );

log1p( x )

Computes the natural logarithm of 1+x.

var val = log1p( 4 );
// returns ~1.609

val = log1p( -1 );
// returns -infinity

val = log1p( Number.POSITIVE_INFINITY );
// returns +infinity

For x < -1, the function returns NaN, as the natural logarithm is not defined for negative numbers.

var val = log1p( -2 );
// returns NaN

Examples

var round = require( 'math-round' );
var log1p = require( 'math-float64-log1p' );

var x;
var i;

for ( i = 0; i < 100; i++ ) {
	x = round( Math.random() * 100 );
	console.log( log1p( x ) );
}

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

$ node ./examples/index.js

Tests

Unit

This repository uses tape 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 Istanbul 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 Testling 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

License

MIT license.

Copyright

Copyright © 2016. The Compute.io Authors.