mean, median, mode (#83)

* mean median mode

* update DIRECTORY

* just renaming

* adding unit tests

* organizing the file

* ops missed this one

DIRECTORY.md

@@ -24,6 +24,9 @@
   * [Fibonacci2](./Maths/Fibonacci2.php)
   * [Neonnumber](./Maths/NeonNumber.php)
   * [Perfectsquare](./Maths/PerfectSquare.php)
+  * [Mean](./Maths/Mean.php)
+  * [Median](./Maths/Median.php)
+  * [Mode](./Maths/Mode.php)
   * Projecteuler
     * [Problem1](./Maths/ProjectEuler/Problem1.php)
     * [Problem2](./Maths/ProjectEuler/Problem2.php)

Maths/Mean.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * This function calculates
+ * The mean value of
+ * numbers provided
+ * 
+ * @param decimal $numbers A variable sized number input
+ * @return decimal $mean Mean of provided numbers
+ */
+function mean(...$numbers)
+{
+    if (empty($numbers)) {
+        throw new \Exception('Please pass values to find mean value');
+    }
+
+    $total = array_sum($numbers);
+    $mean = $total / count($numbers);
+    
+    return $mean;
+}

Maths/Median.php

@@ -0,0 +1,22 @@
+<?php
+/**
+ * This function calculates
+ * The median value of
+ * numbers provided
+ * 
+ * @param decimal $numbers A variable sized number input
+ * @return decimal $median Median of provided numbers
+ */
+function median(...$numbers)
+{
+    if (empty($numbers)) {
+        throw new \Exception('Please pass values to find mean value');
+    }
+
+    sort($numbers);
+    $length = count($numbers);
+    
+    $middle = $length >> 1;
+    $median = ($numbers[$middle] + $numbers[$middle - 1]) / 2;
+    return $median;
+}

Maths/Mode.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * This function calculates
+ * The mode value of
+ * numbers provided
+ * 
+ * @param decimal $numbers A variable sized number input
+ * @return decimal $mode Mode of provided numbers
+ */
+function mode(...$numbers)
+{
+    if (empty($numbers)) {
+        throw new \Exception('Please pass values to find mean value');
+    }
+
+    $values = array_count_values($numbers); 
+    $mode = array_search(max($values), $values);
+
+    return $mode;
+}

tests/Maths/MathsTest.php

@@ -17,6 +17,9 @@ require_once __DIR__ . '/../../Maths/Fibonacci.php';
 require_once __DIR__ . '/../../Maths/Fibonacci2.php';
 require_once __DIR__ . '/../../Maths/NeonNumber.php';
 require_once __DIR__ . '/../../Maths/PerfectSquare.php';
+require_once __DIR__ . '/../../Maths/Mean.php';
+require_once __DIR__ . '/../../Maths/Median.php';
+require_once __DIR__ . '/../../Maths/Mode.php';
 
 class MathsTest extends TestCase
 {
@@ -29,8 +32,7 @@ class MathsTest extends TestCase
         factorial(-25);
     }
 
-public function testIsNumberArmstrong()
-
+    public function testIsNumberArmstrong()
     {
         assertTrue(isNumberArmstrong(153));
         assertFalse(isNumberArmstrong(123));
@@ -38,8 +40,7 @@ public function testIsNumberArmstrong()
         assertFalse(isNumberArmstrong(2468));
     }
 
-public function testIsNumberPalindromic()
-
+    public function testIsNumberPalindromic()
     {
         assertTrue(isNumberPalindromic(121));
         assertFalse(isNumberPalindromic(123));
@@ -106,6 +107,7 @@ public function testIsNumberPalindromic()
         assertFalse(isNumberNeon(123));
         assertTrue(isNumberNeon(9));
     }
+    
     public function testFibonacciGenerator()
     {
         assertEquals([0, 1, 1, 2, 3], iterator_to_array(loop(5, fib())));
@@ -114,4 +116,25 @@ public function testIsNumberPalindromic()
         assertEquals([0, 1, 1, 2, 3], iterator_to_array(loop(5, fib())));
         assertEquals([0, 1, 1, 2, 3, 5, 8, 13, 21, 34], iterator_to_array(loop(10, fib())));
     }
+
+    public function testMean()
+    {
+        mean(2,3,9,6);
+        mean(7);
+        mean(42,77,89,35);
+    }
+
+    public function testMedian()
+    {
+        median(1,2,8,11);
+        median(40,90);
+        median(35,66,91,27);
+    }
+
+    public function testMode()
+    {
+        mode(4,2,7,9,2,9,0,4,2);
+        mode(21,72,40,21,0,99,21,99,0,40);
+        mode(3,3,3,3);
+    }
 }