Add support for the object and chain methods to the mean and median.

Author: javadev

math-plugin/src/main/java/com/github/underscore/math/$.java

@@ -45,6 +45,14 @@ public Chain(final List<T> list) {
         public <T extends Number> Chain<T> sum() {
             return new Chain<T>($.sum((List<T>) value()));
         }
+
+        public Chain<Double> mean() {
+            return new Chain<Double>($.mean((List<Number>) value()));
+        }
+
+        public Chain<Double> median() {
+            return new Chain<Double>($.median((List<Number>) value()));
+        }
     }
 
     public static <T> Chain chain(final List<T> list) {
@@ -139,6 +147,10 @@ public static <T extends Number> double mean(final Iterable<T> iterable) {
         return result.doubleValue() / count;
     }
 
+    public double mean() {
+        return mean((Iterable<Number>) getIterable());
+    }
+
     public static <T extends Number> double median(final Iterable<T> iterable) {
         final List<T> result = newArrayList((Collection) iterable);
         final int size = size(iterable);
@@ -148,6 +160,10 @@ public static <T extends Number> double median(final Iterable<T> iterable) {
         return (result.get(size / 2 - 1).doubleValue() + result.get(size / 2).doubleValue()) / 2;
     }
 
+    public double median() {
+        return median((Iterable<Number>) getIterable());
+    }
+
     public static void main(String[] args) {
         final String message = "Underscore-java-math is a math plugin for underscore-java.\n\n"
             + "For docs, license, tests, and downloads, see: http://javadev.github.io/underscore-java";

math-plugin/src/test/java/com/github/underscore/math/MathTest.java

@@ -110,6 +110,10 @@ public double doubleValue() {
     public void mean() {
         final Double result = $.mean(asList((double) 0, (double) 0.5, (double) 1));
         assertEquals("0.5", result.toString());
+        final Double resultObj = new $(asList((double) 0, (double) 0.5, (double) 1)).mean();
+        assertEquals("0.5", resultObj.toString());
+        final Double resultChain = (Double) $.chain(asList((double) 0, (double) 0.5, (double) 1)).mean().item();
+        assertEquals("0.5", resultChain.toString());
         final Double result2 = $.mean(asList((long) 0, (long) 1, (long) 2));
         assertEquals("1.0", result2.toString());
     }
@@ -128,6 +132,10 @@ public void mean() {
     public void median() {
         final Double result = $.median(asList((int) 0, (int) 0, (int) 0, (int) 0, (int) 5));
         assertEquals("0.0", result.toString());
+        final Double resultObj = new $(asList((int) 0, (int) 0, (int) 0, (int) 0, (int) 5)).median();
+        assertEquals("0.0", resultObj.toString());
+        final Double resultChain = (Double) $.chain(asList((int) 0, (int) 0, (int) 0, (int) 0, (int) 5)).median().item();
+        assertEquals("0.0", resultChain.toString());
         final Double result2 = $.median(asList((int) 0, (int) 0, (int) 1, (int) 2, (int) 5));
         assertEquals("1.0", result2.toString());
         final Double result3 = $.median(asList((int) 0, (int) 0, (int) 1, (int) 2));