Merge pull request #1 from compute-io/develop

Closes compute-io/todo#41

.gitattributes

@@ -0,0 +1 @@
+* text=auto

.jshintignore

@@ -0,0 +1,14 @@
+
+# Directories #
+###############
+build/
+reports/
+dist/
+
+# Node.js #
+###########
+/node_modules/
+
+# Git #
+#######
+.git*

.jshintrc

@@ -68,4 +68,4 @@
 	"wsh": false,
 	"yui": false,
 	"globals": {}
-}
+}

.npmignore

@@ -13,6 +13,7 @@ examples/
 reports/
 support/
 test/
+benchmark/
 
 # Node.js #
 ###########
@@ -46,5 +47,6 @@ Desktop.ini
 # Utilities #
 #############
 .jshintrc
+.jshintignore
 .travis.yml
 .editorconfig

.travis.yml

@@ -1,5 +1,12 @@
 language: node_js
 node_js:
-  - "0.10"
+  - '0.12'
+  - '0.11'
+  - '0.10'
+  - '0.8'
+  - 'iojs'
+before_install:
+  - npm update -g npm
 after_script:
-  - npm run coveralls
+  - npm run coveralls
+

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2014 Athan Reines.
+Copyright (c) 2014-2015 The Compute.io Authors. All rights reserved.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -18,4 +18,4 @@ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+SOFTWARE.

Makefile

@@ -5,32 +5,42 @@
 # Set the node.js environment to test:
 NODE_ENV ?= test
 
+# Kernel name:
+KERNEL ?= $(shell uname -s)
+
+ifeq ($(KERNEL), Darwin)
+	OPEN ?= open
+else
+	OPEN ?= xdg-open
+endif
 
 # NOTES #
 
-NOTES ?= 'TODO|FIXME'
+NOTES ?= 'TODO|FIXME|WARNING|HACK|NOTE'
 
 
 # MOCHA #
 
-# Specify the test framework bin locations:
 MOCHA ?= ./node_modules/.bin/mocha
 _MOCHA ?= ./node_modules/.bin/_mocha
-
-# Specify the mocha reporter:
 MOCHA_REPORTER ?= spec
 
 
 # ISTANBUL #
 
-# Istanbul configuration:
 ISTANBUL ?= ./node_modules/.bin/istanbul
 ISTANBUL_OUT ?= ./reports/coverage
 ISTANBUL_REPORT ?= lcov
 ISTANBUL_LCOV_INFO_PATH ?= $(ISTANBUL_OUT)/lcov.info
 ISTANBUL_HTML_REPORT_PATH ?= $(ISTANBUL_OUT)/lcov-report/index.html
 
 
+# JSHINT #
+
+JSHINT ?= ./node_modules/.bin/jshint
+JSHINT_REPORTER ?= ./node_modules/jshint-stylish/stylish.js
+
+
 
 # FILES #
 
@@ -96,9 +106,20 @@ test-istanbul-mocha: node_modules
 view-cov: view-istanbul-report
 
 view-istanbul-report:
-	open $(ISTANBUL_HTML_REPORT_PATH)
+	$(OPEN) $(ISTANBUL_HTML_REPORT_PATH)
 
 
+# LINT #
+
+.PHONY: lint lint-jshint
+
+lint: lint-jshint
+
+lint-jshint: node_modules
+	$(JSHINT) \
+		--reporter $(JSHINT_REPORTER) \
+		./
+
 
 # NODE #
 
@@ -117,7 +138,6 @@ clean-node:
 
 
 # CLEAN #
-
 .PHONY: clean
 
 clean:

README.md

@@ -2,7 +2,7 @@ Subtract
 ===
 [![NPM version][npm-image]][npm-url] [![Build Status][travis-image]][travis-url] [![Coverage Status][coveralls-image]][coveralls-url] [![Dependencies][dependencies-image]][dependencies-url]
 
-> Computes an element-wise subtraction of a numeric array.
+> Computes an element-wise subtraction.
 
 
 ## Installation
@@ -16,40 +16,117 @@ For use in the browser, use [browserify](https://github.com/substack/node-browse
 
 ## Usage
 
-To use the module,
-
 ``` javascript
 var subtract = require( 'compute-subtract' );
 ```
 
-#### subtract( arr, x )
+#### subtract( arr, x[, opts] )
 
-Computes an element-wise subtraction of an input `array`. `x` may be either an `array` of equal length or a scalar.
+Computes an element-wise subtraction. `x` may be either an `array` of equal length or a `numeric` value.
 
 ``` javascript
-subtract( [ 2, 1, 4, 2 ], 1 );
+var arr = [ 2, 1, 4, 2 ],
+	out;
+
+out = subtract( arr, 1 );
 // returns [ 1, 0, 3, 1 ]
 
-subtract( [ 2, 1, 4, 2 ], [ 1, 2, 3, 3 ] );
+out = subtract( arr, [ 1, 2, 3, 3 ] );
 // returns [ 1, -1, 1, -1 ]
 ```
 
+The function accepts the following `options`:
+
+*  __copy__: `boolean` indicating whether to return a new `array`. Default: `true`.
+*  __accessor__: accessor `function` for accessing values in object `arrays`.
+
+To mutate the input `array` (e.g., when input values can be discarded or when optimizing memory usage), set the `copy` option to `false`.
+
+``` javascript
+var arr = [ 5, 3, 8, 3, 2 ];
+
+var out = subtract( arr, 4, {
+	'copy': false
+});
+// returns [ 1, -1, 4, -1, -2 ]
+
+console.log( arr === out );
+// returns true
+```
+
+__Note__: mutation is the `array` equivalent of a __minus-equal__ (`-=`).
+
+For object `arrays`, provide an accessor `function` for accessing `array` values.
+
+``` javascript
+var data = [
+	['beep', 5],
+	['boop', 3],
+	['bip', 8],
+	['bap', 3],
+	['baz', 2]
+];
+
+function getValue( d, i ) {
+	return d[ 1 ];
+}
+
+var out = subtract( data, 4, {
+	'accessor': getValue
+});
+// returns [ 1, -1, 4, -1, -2 ]
+```
+
+When subtracting values between two object `arrays`, provide an accessor `function` which accepts `3` arguments.
+
+``` javascript
+var data = [
+	['beep', 5],
+	['boop', 3],
+	['bip', 8],
+	['bap', 3],
+	['baz', 2]
+];
+
+var arr = [
+	{'x': 4},
+	{'x': 5},
+	{'x': 6},
+	{'x': 5},
+	{'x': 3}
+];
+
+function getValue( d, i, j ) {
+	if ( j === 0 ) {
+		return d[ 1 ];
+	}
+	return d.x;
+}
+
+var out = subtract( data, arr, {
+	'accessor': getValue
+});
+// returns [ 1, -2, 2, -2, -1 ]
+```
+
+__Note__: `j` corresponds to the input `array` index, where `j=0` is the index for the first input `array` and `j=1` is the index for the second input `array`.
+
+
+
 
 ## Examples
 
 ``` javascript
 var subtract = require( 'compute-subtract' );
 
-// Simulate some data...
 var data = new Array( 100 );
-
 for ( var i = 0; i < data.length; i++ ) {
 	data[ i ] = Math.round( Math.random()*100 );
 }
 
-subtract( data, 10 );
+var out = subtract( data, 10 );
 
-console.log( data.join( '\n' ) );
+console.log( out.join( '\n' ) );
 ```
 
 To run the example code from the top-level application directory,
@@ -58,23 +135,12 @@ To run the example code from the top-level application directory,
 $ node ./examples/index.js
 ```
 
-## Notes
-
-This function mutates the input `array`. If mutation is undesired,
-
-``` javascript
-var data = [ 1, 2, 3, 4 ],
-	copy = data.slice();
-
-subtract( copy, 2 );
-```
-
 
 ## Tests
 
 ### Unit
 
-Unit tests use the [Mocha](http://visionmedia.github.io/mocha) test framework with [Chai](http://chaijs.com) assertions. To run the tests, execute the following command in the top-level application directory:
+Unit tests use the [Mocha](http://mochajs.org) test framework with [Chai](http://chaijs.com) assertions. To run the tests, execute the following command in the top-level application directory:
 
 ``` bash
 $ make test
@@ -98,15 +164,15 @@ $ make view-cov
 ```
 
 
+---
 ## License
 
 [MIT license](http://opensource.org/licenses/MIT). 
 
 
----
 ## Copyright
 
-Copyright &copy; 2014. Athan Reines.
+Copyright &copy; 2014-2015. The Compute.io Authors.
 
 
 [npm-image]: http://img.shields.io/npm/v/compute-subtract.svg

examples/index.js

@@ -2,13 +2,10 @@
 
 var subtract = require( './../lib' );
 
-// Simulate some data...
 var data = new Array( 100 );
-
 for ( var i = 0; i < data.length; i++ ) {
 	data[ i ] = Math.round( Math.random()*100 );
 }
+var out = subtract( data, 10 );
 
-subtract( data, 10 );
-
-console.log( data.join( '\n' ) );
+console.log( out.join( '\n' ) );