diff --git a/Modules/PhotoacousticsLib/include/mitkPASpectralUnmixingFilterSimplex.h b/Modules/PhotoacousticsLib/include/mitkPASpectralUnmixingFilterSimplex.h
index 47bb93f820..f463f57177 100644
--- a/Modules/PhotoacousticsLib/include/mitkPASpectralUnmixingFilterSimplex.h
+++ b/Modules/PhotoacousticsLib/include/mitkPASpectralUnmixingFilterSimplex.h
@@ -1,41 +1,52 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef MITKPHOTOACOUSTICSPECTRALUNMIXINGFILTERSIMPLEX_H
 #define MITKPHOTOACOUSTICSPECTRALUNMIXINGFILTERSIMPLEX_H
 
 #include <mitkPASpectralUnmixingFilterBase.h>
 #include <MitkPhotoacousticsLibExports.h>
 
 namespace mitk {
   namespace pa {
     class MITKPHOTOACOUSTICSLIB_EXPORT SpectralUnmixingFilterSimplex : public SpectralUnmixingFilterBase
     {
     public:
 
       mitkClassMacro(SpectralUnmixingFilterSimplex, SpectralUnmixingFilterBase)
-        //itkFactorylessNewMacro(Self)
-     
+        itkFactorylessNewMacro(Self)
+
     protected:
       SpectralUnmixingFilterSimplex();
       virtual ~SpectralUnmixingFilterSimplex();
 
     private:
+      int factorial(int n);
+
+      virtual Eigen::VectorXf SpectralUnmixingAlgorithm(Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> EndmemberMatrix,
+        Eigen::VectorXf inputVector) override;
+
+      Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> GenerateA(Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> EndmemberMatrix,
+        Eigen::VectorXf inputVector, int i);
+
+
+      Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> GenerateD2(Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> A);
+      float simplexVolume(Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> Matrix);
 
     };
   }
 }
 #endif // MITKPHOTOACOUSTICSPECTRALUNMIXINGFILTERSIMPLEX_H
diff --git a/Modules/PhotoacousticsLib/src/SUFilter/mitkPASpectralUnmixingFilterSimplex.cpp b/Modules/PhotoacousticsLib/src/SUFilter/mitkPASpectralUnmixingFilterSimplex.cpp
index 552b11bd35..9aed1ca170 100644
--- a/Modules/PhotoacousticsLib/src/SUFilter/mitkPASpectralUnmixingFilterSimplex.cpp
+++ b/Modules/PhotoacousticsLib/src/SUFilter/mitkPASpectralUnmixingFilterSimplex.cpp
@@ -1,32 +1,115 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
-#include "mitkPASpectralUnmixingFilterSimplex.h"
+#include <mitkPASpectralUnmixingFilterSimplex.h>
 
 // Includes for AddEnmemberMatrix
-#include "mitkPAPropertyCalculator.h"
 #include <eigen3/Eigen/Dense>
 
+#include <cmath>
 
 mitk::pa::SpectralUnmixingFilterSimplex::SpectralUnmixingFilterSimplex()
 {
 
 }
 
 mitk::pa::SpectralUnmixingFilterSimplex::~SpectralUnmixingFilterSimplex()
 {
 
 }
+
+Eigen::VectorXf mitk::pa::SpectralUnmixingFilterSimplex::SpectralUnmixingAlgorithm(
+  Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> EndmemberMatrix, Eigen::VectorXf inputVector)
+{
+  int numberOfChromophores = EndmemberMatrix.cols();
+  Eigen::VectorXf resultVector(numberOfChromophores);
+
+  float VolumeMax = simplexVolume(EndmemberMatrix);
+  for (int i = 0; i < numberOfChromophores; ++i)
+  {
+    Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> A = GenerateA(EndmemberMatrix, inputVector, i);
+    float Volume = simplexVolume(A);
+    resultVector[i] = Volume / VolumeMax;
+  }
+
+  return resultVector;
+}
+
+Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> GenerateA(Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> EndmemberMatrix,
+  Eigen::VectorXf inputVector, int i)
+{
+  Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> A = EndmemberMatrix;
+  int numberOfChromophores = EndmemberMatrix.cols();
+
+  for (int j = 0; j < numberOfChromophores; ++j)
+  {
+    A(i, j) = inputVector(j);
+  }
+
+  return A;
+}
+
+Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> GenerateD2(Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> A)
+{
+  Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> D2;
+  int numberOfChromophores = A.cols();
+
+  for (int i = 0; i < numberOfChromophores; ++i)
+  {
+    for (int j = 0; j < numberOfChromophores; ++j)
+    {
+      Eigen::VectorXf x = A.col(i) - A.col(j);
+      D2(i, j) = x.dot(x);
+    }
+  }
+
+  return D2;
+}
+
+float simplexVolume(Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> Matrix)
+{
+  float Volume;
+  int numberOfChromophores = Matrix.cols();
+  Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> C;
+  Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic> D2 = GenerateD2(Matrix);
+
+  for (int i = 0; i < numberOfChromophores; ++i)
+  {
+    for (int j = 0; j < numberOfChromophores; ++j)
+    {
+      C(i, j) = D2(i, j);
+    }
+    C(i, numberOfChromophores) = 1;
+    for (int k = 0; k < numberOfChromophores; ++k)
+    {
+      C(numberOfChromophores, k) = 1;
+    }
+    C(numberOfChromophores, numberOfChromophores) = 0;
+  }
+
+  float detC = C.determinant();// determinate von C
+  float denominator = (factorial(numberOfChromophores-1) ^ 2 * 2 ^ (numberOfChromophores - 1)*(-1) ^ numberOfChromophores;
+
+  return Volume;
+}
+
+int factorial(int n)
+{
+  if (n == 1)
+    return 1;
+  else
+    return n * factorial(n - 1);
+}