Lorenz implemented

Math/Finance/Lorenzkurve.php

@@ -0,0 +1,45 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.0
+ *
+ * @category   TBD
+ * @package    TBD
+ * @author     OMS Development Team <dev@oms.com>
+ * @author     Dennis Eichhorn <d.eichhorn@oms.com>
+ * @copyright  2013 Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @link       http://orange-management.com
+ */
+namespace phpOMS\Math\Finance;
+
+/**
+ * Finance class.
+ *
+ * @category   Log
+ * @package    Framework
+ * @author     OMS Development Team <dev@oms.com>
+ * @author     Dennis Eichhorn <d.eichhorn@oms.com>
+ * @license    OMS License 1.0
+ * @link       http://orange-management.com
+ * @since      1.0.0
+ */
+class Lorenzkurve
+{
+    public static function getGiniCoefficient(array $data)
+    {
+        $sum1 = 0;
+        $sum2 = 0;
+        $i    = 1;
+        $n    = count($data);
+
+        foreach ($data as $key => $value) {
+            $sum1 += $i * $value;
+            $sum2 += $value;
+        }
+
+        return 2 * $sum1 / ($n * $sum2) - ($n + 1) / $n;
+    }
+}