diff --git a/Math/Matrix/QRDecomposition.php b/Math/Matrix/QRDecomposition.php
index 25459b0ea..5c6dbbb66 100644
--- a/Math/Matrix/QRDecomposition.php
+++ b/Math/Matrix/QRDecomposition.php
@@ -83,7 +83,7 @@ final class QRDecomposition
                 $nrm = Triangle::getHypot($nrm, $this->QR[$i][$k]);
             }
 
-            if ($nrm != 0.0) {
+            if ($nrm != 0) {
                 // Form k-th Householder vector.
                 if ($this->QR[$k][$k] < 0) {
                     $nrm = -$nrm;
diff --git a/Math/Matrix/SingularValueDecomposition.php b/Math/Matrix/SingularValueDecomposition.php
index b96a13157..14e113912 100644
--- a/Math/Matrix/SingularValueDecomposition.php
+++ b/Math/Matrix/SingularValueDecomposition.php
@@ -24,4 +24,109 @@ namespace phpOMS\Math\Matrix;
  */
 final class SingularValueDecomposition
 {
+    /**
+     * U matrix.
+     *
+     * @var array[]
+     * @since 1.0.0
+     */
+    private $U = [];
+
+    /**
+     * V matrix.
+     *
+     * @var array[]
+     * @since 1.0.0
+     */
+    private $V = [];
+
+    /**
+     * Singular values.
+     *
+     * @var array
+     * @since 1.0.0
+     */
+    private $S = [];
+
+    /**
+     * Dimension m
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    private $m = 0;
+
+    /**
+     * Dimension n
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    private $n = 0;
+
+    public function getU() : Matrix
+    {
+        $matrix = new Matrix();
+        $matrix->setMatrix($this->U);
+
+        return $matrix;
+    }
+
+    public function getV() : Matrix
+    {
+        $matrix = new Matrix();
+        $matrix->setMatrix($this->V);
+
+        return $matrix;
+    }
+
+    public function getS() : Matrix
+    {
+        $S = [[]];
+        for ($i = 0; $i < $this->n; ++$i) {
+            for ($j = 0; $j < $this->n; ++$j) {
+                $S[$i][$j] = 0.0;
+            }
+            $S[$i][$i] = $this->s[$i];
+        }
+        
+        $matrix = new Matrix();
+        $matrix->setMatrix($this->V);
+
+        return $matrix;
+    }
+
+    public function getSingularValues() : Vector
+    {
+        $vector = new Vector();
+        $vector->setMatrix($this->S);
+
+        return $vector;
+    }
+
+    public function norm2() : float
+    {
+        return $this->S[0];
+    }
+
+    public function cond() : float
+    {
+        return $this->S[0] / $this->S[\min($this->m, $this->n) - 1];
+    }
+
+    public function rank() : int
+    {
+        $eps = 0.00001;
+        $tol = \max($this->m, $this->n) * $this->S[0] * $eps;
+        $r   = 0;
+
+        $length = \count($this->S);
+        for ($i = 0; $i < $length; ++$i) {
+            if ($this->S[$i] > $tol) {
+                ++$r;
+            }
+        }
+
+        return $r;
+    }
 }
diff --git a/tests/Math/Matrix/QRDecompositionTest.php b/tests/Math/Matrix/QRDecompositionTest.php
index f6f7ddc45..46af3ef79 100644
--- a/tests/Math/Matrix/QRDecompositionTest.php
+++ b/tests/Math/Matrix/QRDecompositionTest.php
@@ -19,7 +19,7 @@ use phpOMS\Math\Matrix\QRDecomposition;
 
 class QRDecompositionTest extends \PHPUnit\Framework\TestCase
 {
-    /**public function testDecomposition()
+    public function testDecomposition()
     {
         $A = new Matrix();
         $A->setMatrix([
@@ -32,24 +32,26 @@ class QRDecompositionTest extends \PHPUnit\Framework\TestCase
 
         self::assertTrue($QR->isFullRank());
 
+        self::assertEquals([
+            [-6 / 7, 69 / 175, 58 / 175],
+            [-3 / 7, -158 / 175, -6 / 175],
+            [2 / 7, -6 / 35, 33 / 35],
+        ], $QR->getQ()->toArray(), '', 0.2);
+
+        self::assertEquals([
+            [-14, -21, 14],
+            [0, -175, 70],
+            [0, 0, -35],
+        ], $QR->getR()->toArray(), '', 0.2);
+
+        self::assertEquals($A->toArray(), $QR->getQ()->mult($QR->getR()), '', 0.2);
+
         self::assertEquals([
             [12, -69, -58 / 5],
             [6, 158, 6 / 5],
             [-4, 30, -33],
         ], $QR->getH()->toArray(), '', 0.2);
-
-        self::assertEquals([
-            [6 / 7, -69 / 175, -58 / 175],
-            [3 / 7, 158 / 175, 6 / 175],
-            [-2 / 7, 6 / 35, -33 / 35],
-        ], $QR->getQ()->toArray(), '', 0.2);
-
-        self::assertEquals([
-            [14, 21, -14],
-            [0, 175, -70],
-            [0, 0, 35],
-        ], $QR->getR()->toArray(), '', 0.2);
-    }*/
+    }
 
     public function testSolve()
     {
diff --git a/tests/Math/Matrix/SingularValueDecompositionTest.php b/tests/Math/Matrix/SingularValueDecompositionTest.php
new file mode 100644
index 000000000..b394f11c9
--- /dev/null
+++ b/tests/Math/Matrix/SingularValueDecompositionTest.php
@@ -0,0 +1,26 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.2
+ *
+ * @package    tests
+ * @copyright  Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @link       http://website.orange-management.de
+ */
+
+namespace phpOMS\tests\Math\Matrix;
+
+use phpOMS\Math\Matrix\Matrix;
+use phpOMS\Math\Matrix\Vector;
+use phpOMS\Math\Matrix\SingularValueDecomposition;
+
+class SingularValueDecompositionTest extends \PHPUnit\Framework\TestCase
+{
+    public function testPlaceholder()
+    {
+        self::markTestIncomplete();
+    }
+}