linspace

Generates a linearly spaced numeric array.

Installation

$ npm install compute-linspace

For use in the browser, use browserify.

Usage

To use the module,

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

linspace( start, stop[, length] )

Generates a linearly spaced numeric array. If a length is not provided, the default output array length is 100.

var arr = linspace( 0, 100, 6 );
// returns [ 0, 20, 40, 60, 80, 100 ]

Notes

The output array is guaranteed to include the start and end values. Beware, however, that values between the start and end are subject to floating point errors. Hence,

var arr = linspace( 0, 1, 3 );
// returns [ 0, ~0.5, 1 ]

where arr[1] is only guaranteed to be approximately equal to 0.5. If you desire more control over element precision, consider using compute-roundn:

var roundn = require( 'compute-roundn' );
 
// Create an array subject to floating point errors:
var arr = linspace( 0, 1, 21 );
 
// Round each value to the nearest hundredth:
roundn( arr, -2 );
 
console.log( arr.join( '\n' ) );

This function is inspired by MATLAB's linspace.

Examples

var linspace = require( 'compute-linspace' ),
    out;
 
// Default behavior:
out = linspace( 0, 10 );
console.log( out.join( '\n' ) );
 
// Specify length:
out = linspace( 0, 10, 10 );
console.log( out.join( '\n' ) );
 
out = linspace( 0, 10, 11 );
console.log( out.join( '\n' ) );
 
// Create an array with decremented values:
out = linspace( 10, 0, 11 );
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.