compute-logspace

logspace

Generates a logarithmically spaced numeric array.

Installation

$ npm install compute-logspace

For use in the browser, use browserify.

Usage

To use the module,

var logspace = require( 'compute-logspace' );

logspace( a, b[, length] )

Generates a logarithmically spaced numeric array between 10^a and 10^b. If a length is not provided, the default output array length is 10.

var arr = logspace( 0, 2, 6 );
// returns [ 1, ~2.5, ~6.31, ~15.85, ~39.81, 100 ]

Notes

The output array includes the values 10^a and 10^b. Beware of floating point errors, including for the first and last array elements.

This function is inspired by MATLAB's logspace and NumPy's logspace.

Examples

var logspace = require( 'compute-logspace' ),
    out;
 
// Default behavior:
out = logspace( 0, 3 );
console.log( out.join( '\n' ) );
 
// Specify length:
out = logspace( 0, 3, 100 );
console.log( out.join( '\n' ) );
 
// Create an array with decremented values:
out = logspace( 3, 0, 10 );
console.log( out.join( '\n' ) );

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

$ node ./examples/index.js

Tests

Unit

Unit tests use the Mocha test framework with Chai assertions. 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

License

MIT license.

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Copyright

Copyright © 2014. Athan Reines.