Add mean filter.

README.md

@@ -68,6 +68,7 @@
   - [shortFmt](#shortfmt)
   - [byteFmt](#bytefmt)
   - [kbFmt](#kbfmt)
+  - [mean](#mean)
 - [Boolean](#boolean)
   - [isNull](#isnull)
   - [isDefined](#isdefined)
@@ -1190,6 +1191,14 @@ Converts kilobytes into formatted display<br/>
 1 MB
 1.00126 GB
 
+```
+###mean
+Calculates the mean value from all values within an array<br/>
+**Usage:** ```array | mean```
+```html
+{{ [12,7,5] | mean }}
+<!--result
+8
 ```
 #Boolean
 >Used for boolean expression in chaining filters

src/_filter/math/mean.js

@@ -0,0 +1,40 @@
+/**
+ * @ngdoc filter
+ * @name mean
+ * @kind function
+ *
+ * @description
+ * Math.mean will get an array and return the mean value. if an expression
+ * is provided, will return mean value by expression.
+ */
+
+angular.module('a8m.math.mean', ['a8m.math', 'a8m.math.sum'])
+
+  .filter('mean', ['$math', 'sumFilter', function ($math, sumFilter) {
+    return function (input) {
+
+	  if(!isArray(input) || !isNumericArray(input)){
+	    return input;
+	  }
+
+      return sumFilter(input) / input.length;
+    };
+
+	/**
+	 * Check if the given array is numeric.
+	 * @private
+	 * @param array An array given by the input.
+	 * @returns {boolean}
+	 */
+	function isNumericArray(array){
+		var result = true;
+		forEach(array, function(element){
+			if(!isNumber(element)){
+				result = false;
+				return;
+			}
+		});
+		return result;
+	}
+
+  }]);

src/filters.js

@@ -63,6 +63,7 @@ angular.module('angular.filter', [
   'a8m.math.byteFmt',
   'a8m.math.kbFmt',
   'a8m.math.shortFmt',
+  'a8m.math.mean',
 
   'a8m.angular',
   'a8m.conditions',

test/spec/filter/math/mean.js

@@ -0,0 +1,28 @@
+'use strict';
+
+describe('meanFilter', function () {
+
+  var filter;
+
+  beforeEach(module('a8m.math.mean'));
+
+  beforeEach(inject(function ($filter) {
+    filter = $filter('mean');
+  }));
+
+  it('should return the mean of all members in array', function() {
+    expect(filter([1,2,3,4,5,6])).toEqual(3.5);
+    expect(filter([0,0,0,0,0,3])).toEqual(0.5);
+  });
+
+  it('should return an object if the members type != number', function() {
+    expect(typeof filter([{}, 'string', 'foo'])).toEqual('object')
+  });
+
+  it('should return the input as-is if is not an array', function() {
+    expect(filter('string')).toEqual('string');
+    expect(filter(1)).toEqual(1);
+    expect(filter(!1)).toBeFalsy();
+  })
+
+});