Merge pull request #50 from agungsantoso/master

Add Silver Ratio Constant. Thanks to @agungsantoso .

Author: castarco

src/DecimalConstants.php

@@ -22,6 +22,8 @@ final class DecimalConstants
 
     private static $GoldenRatio = null;
 
+    private static $SilverRatio = null;
+
     private static $LightSpeed = null;
 
     /**
@@ -123,6 +125,20 @@ public static function goldenRatio()
         return self::$GoldenRatio;
     }
 
+    /**
+     * Returns the Silver Ratio.
+     * @return Decimal
+     */
+    public static function silverRatio()
+    {
+        if (self::$SilverRatio === null) {
+            self::$SilverRatio = Decimal::fromString(
+                "2.41421356237309504880168872420970"
+            );
+        }
+        return self::$SilverRatio;
+    }
+
     /**
      * Returns the Light of Speed measured in meters / second.
      * @return Decimal

tests/DecimalConstantsTest.php

@@ -23,6 +23,10 @@ public function testFiniteAbs()
             Decimal::fromString("1.61803398874989484820458683436564")
         ));
 
+        $this->assertTrue(DecimalConstants::silverRatio()->equals(
+            Decimal::fromString("2.41421356237309504880168872420970")
+        ));
+
         $this->assertTrue(DecimalConstants::lightSpeed()->equals(
             Decimal::fromInteger(299792458)
         ));