merged featureMatrixCalculator to pullrequest

src/main/java/com/ugsbo/gui/BasicGuiController.java

@@ -5,9 +5,9 @@ import javafx.scene.control.*;
 
 public class BasicGuiController {
 
-    //Hier werden die fx:id Attribute verknuepft.
+    // Hier werden die fx:id Attribute verknuepft.
     @FXML
-    private Button app1; //Fuer ToDoManager.
+    private Button matrixCalc;
     @FXML
     private Button app2; //Fuer VokabelKartenSchreiber
     @FXML
@@ -19,7 +19,7 @@ public class BasicGuiController {
      * Konstructor is called before initialize()
      */
     public BasicGuiController() {
-        //Setup of some Fields could be defined here.
+        // Setup of some Fields could be defined here.
     }
 
     /**
@@ -28,9 +28,9 @@ public class BasicGuiController {
      */
     @FXML
     public void initialize() {
-        app1.setOnMouseClicked((event) -> {
-            //MainApp.startToDoMainGui();
-            System.out.println(event);
+        matrixCalc.setOnMouseClicked((event) -> {
+            MainApp.startMatrixCalcGUI();
+            // System.out.println(event);
         });
         app2.setOnMouseClicked((event) -> {
             //System.out.println(event);

src/main/java/com/ugsbo/gui/MainApp.java

@@ -35,7 +35,7 @@ public class MainApp extends Application {
   /**
    * Loades the FXML file and the Default CSS.
    * 
-   * @param stage        The Stage will be passed over from fxml
+   * @param stage        The Stage will be passed over from JavaFx
    * @param fxmlFileName Only the Filename of the fxml file wich sould be loaded
    */
   private void createStageFromFXML(Stage stage, String fxmlFileName) {
@@ -64,4 +64,14 @@ public class MainApp extends Application {
     MainApp main = new MainApp();
     main.createStageFromFXML(stage, "Voabelkartenschreiber");
   }
+  
+  /**
+   * Startet eine Instanz der MatrixCalcGui.
+   */
+  public static void startMatrixCalcGUI() {
+    Stage stage = new Stage();
+    MainApp app = new MainApp();
+    app.createStageFromFXML(stage, "matrixCalcGui");
+  }
+
 }

src/main/java/com/ugsbo/matrixcalc/MatrixCalcController.java

@@ -0,0 +1,273 @@
+package com.ugsbo.matrixcalc;
+
+import javafx.fxml.FXML;
+import javafx.scene.control.*;
+import javafx.scene.text.Text;
+import javafx.scene.text.TextAlignment;
+
+import java.util.ArrayList;
+
+public class MatrixCalcController {
+
+    private static final String MULTIPLICATION_STRING = "multiplication";
+    private static final String ADDITION_STRING = "addition";
+    private static final String SUBSTRACTION_STRING = "substract";
+    private static final String TRANPOSE_STRING = "transpose";
+    private static final String CALCDETERMINAT_STRING = "calcDeterminate";
+
+    // The fx:id Attributes will be bind here.
+    @FXML
+    private Button multiplyButton, addButton, DetAButton, DetBButton, substractButton, transposeButton;
+    @FXML
+    private Text errorText, outputText;
+    @FXML
+    private TextArea matrixATextArea, matrixBTextArea;
+
+    private MatrixCalcMath math = new MatrixCalcMath();
+    private MatrixCalcIOUtils util = new MatrixCalcIOUtils();
+
+    /**
+     * Konstructor is called before initialize()
+     */
+    public MatrixCalcController() {
+        // Setup of some Fields could be defined here.
+    }
+
+    /**
+     * Initializes the controller class. This method is automatically called after
+     * the fxml file has been loaded.
+     */
+    @FXML
+    public void initialize() {
+        /**
+         * Convert Strings to matricies, multiply them and output the result.
+         */
+        multiplyButton.setOnMouseClicked((event) -> {
+            String stringMatrixA = matrixATextArea.getText();
+            String stringMatrixB = matrixBTextArea.getText();
+            String[] stringMatrix = { stringMatrixA, stringMatrixB };
+
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 2);
+
+            ArrayList<double[][]> matricies = new ArrayList<double[][]>();
+            matricies.add(util.stringToMatrix(stringMatrixA));
+            matricies.add(util.stringToMatrix(stringMatrixB));
+
+            invokeOperation(matricies, MULTIPLICATION_STRING);
+        });
+
+        /**
+         * Convert a String to a matrix, transpose it and output the result.
+         */
+        transposeButton.setOnMouseClicked((event) -> {
+            String stringMatrixA = matrixATextArea.getText();
+            String[] stringMatrix = { stringMatrixA, "" };
+
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 1);
+
+            ArrayList<double[][]> matricies = new ArrayList<double[][]>();
+            matricies.add(util.stringToMatrix(stringMatrixA));
+
+            invokeOperation(matricies, TRANPOSE_STRING);
+        });
+
+        /**
+         * Convert Strings to matricies, add them and output the result.
+         */
+        addButton.setOnMouseClicked((event) -> {
+            String stringMatrixA = matrixATextArea.getText();
+            String stringMatrixB = matrixBTextArea.getText();
+            String[] stringMatrix = { stringMatrixA, stringMatrixB };
+
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 2);
+
+            ArrayList<double[][]> matricies = new ArrayList<double[][]>();
+            matricies.add(util.stringToMatrix(stringMatrixA));
+            matricies.add(util.stringToMatrix(stringMatrixB));
+
+            invokeOperation(matricies, ADDITION_STRING);
+        });
+
+        /**
+         * Convert Strings to matricies, substract them and output the result.
+         */
+        substractButton.setOnMouseClicked((event) -> {
+            String stringMatrixA = matrixATextArea.getText();
+            String stringMatrixB = matrixBTextArea.getText();
+            String[] stringMatrix = { stringMatrixA, stringMatrixB };
+
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 2);
+
+            ArrayList<double[][]> matricies = new ArrayList<double[][]>();
+            matricies.add(util.stringToMatrix(stringMatrixA));
+            matricies.add(util.stringToMatrix(stringMatrixB));
+
+            invokeOperation(matricies, SUBSTRACTION_STRING);
+        });
+
+        /**
+         * Convert the String of the left inputField to a matrix, calculate the Determinate and output it.
+         */
+        DetAButton.setOnMouseClicked((event) -> {
+            String stringMatrixA = matrixATextArea.getText();
+            String[] stringMatrix = { stringMatrixA, "" };
+
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 1);
+
+            ArrayList<double[][]> matricies = new ArrayList<double[][]>();
+            matricies.add(util.stringToMatrix(stringMatrixA));
+
+            invokeOperation(matricies, CALCDETERMINAT_STRING);
+        });
+
+        /**
+         * Convert the String of the right inputField to a matrix, calculate the Determinate and output it.
+         */
+        DetBButton.setOnMouseClicked((event) -> {
+            String stringMatrixB = matrixBTextArea.getText();
+            String[] stringMatrix = { "", stringMatrixB };
+
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 1);
+
+            ArrayList<double[][]> matricies = new ArrayList<double[][]>();
+            matricies.add(util.stringToMatrix(stringMatrixB));
+
+            invokeOperation(matricies, CALCDETERMINAT_STRING);
+        });
+    }
+
+    /**
+     * Invokes the needed operations form the MatrixCalcMath class 
+     * @param matricies Contains both Matricies or onely one Matrix
+     * @param operation One of the global Constats to select wich Operation is needed.
+     */
+    private void invokeOperation(ArrayList<double[][]> matricies, String operation) {
+        if (matricies.size() == 2) {
+            if (operation.equals(MULTIPLICATION_STRING)) {
+                try {
+                    double[][] result = math.matrixMultiplication(matricies.get(0), matricies.get(1));
+
+                    String DisplayableString = util.outputMatrixToOutputText(result);
+
+                    outputText.setText(DisplayableString);
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                } catch (IllegalArgumentException e) {
+
+                    outputText.setText(e.getMessage());
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                }
+            } else if (operation.equals(ADDITION_STRING)) {
+                try {
+                    double[][] result = math.matrixAddition(matricies.get(0), matricies.get(1));
+        
+                    String DisplayableString = util.outputMatrixToOutputText(result);
+        
+                    outputText.setText(DisplayableString);
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                } catch (IllegalArgumentException e) {
+        
+                    outputText.setText(e.getMessage());
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                }
+            } else if (operation.equals(SUBSTRACTION_STRING)) {
+                try {
+                    double[][] result = math.matrixSubstraction(matricies.get(0), matricies.get(1));
+        
+                    String DisplayableString = util.outputMatrixToOutputText(result);
+        
+                    outputText.setText(DisplayableString);
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                } catch (IllegalArgumentException e) {
+        
+                    outputText.setText(e.getMessage());
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                }
+            }
+        }else if (matricies.size() == 1) {
+            if (operation.equals(TRANPOSE_STRING)) {
+                try {
+                    double[][] result = math.matrixTransponation(matricies.get(0));
+        
+                    String DisplayableString = util.outputMatrixToOutputText(result);
+        
+                    outputText.setText(DisplayableString);
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                } catch (IllegalArgumentException e) {
+        
+                    outputText.setText(e.getMessage());
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                }
+            }
+            if (operation.equals(CALCDETERMINAT_STRING)) {
+                try {
+                    double result = math.calcDeterminat(matricies.get(0));
+        
+                    String DisplayableString = Double.toString(result);
+        
+                    outputText.setText(DisplayableString);
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                } catch (IllegalArgumentException e) {
+        
+                    outputText.setText(e.getMessage());
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                } catch (Exception e){
+
+                    outputText.setText(e.getMessage());
+                    outputText.setTextAlignment(TextAlignment.CENTER);
+                }
+            }
+        }
+    }
+
+    /**
+     * Checks the Input and Displays it if the Input is valid.
+     * 
+     * @param stringMatrix            Contains both input matrices if
+     *                                numberOfMarriciesToMatch is 2. If the number
+     *                                is 1 than one of them has to be a empty String
+     * @param numberOfMatricesToMatch If the number is 1 onely one Marix will be
+     *                                verifyed and the other one needs to be an empty
+     *                                String in the stringMatrix
+     */
+    private void checkInputAndDisplayIfInputIsNotValid(String[] stringMatrix, int numberOfMatricesToMatch) {
+        if (numberOfMatricesToMatch == 1 && !stringMatrix[0].equals("")) {
+            try {
+                util.checkInput(stringMatrix[0]);
+            } catch (Exception e) {
+                outputText.setText(e.getMessage() + "A");
+                outputText.setTextAlignment(TextAlignment.CENTER);
+            }
+        } else if (numberOfMatricesToMatch == 1 && !stringMatrix[1].equals("")) {
+            try {
+                util.checkInput(stringMatrix[1]);
+            } catch (Exception e) {
+                outputText.setText(e.getMessage() + "B");
+                outputText.setTextAlignment(TextAlignment.CENTER);
+            }
+        } else if (numberOfMatricesToMatch == 2 && !stringMatrix[0].equals("") && !stringMatrix[1].equals("")) {
+            try {
+                util.checkInput(stringMatrix[0]);
+            } catch (Exception e) {
+                outputText.setText(e.getMessage() + "A");
+                outputText.setTextAlignment(TextAlignment.CENTER);
+            }
+
+            try {
+                util.checkInput(stringMatrix[1]);
+            } catch (Exception e) {
+                outputText.setText(e.getMessage() + "B");
+                outputText.setTextAlignment(TextAlignment.CENTER);
+            }
+        } else if (stringMatrix[0].equals("")) {
+
+            outputText.setText("Pease insert MatrixA");
+            outputText.setTextAlignment(TextAlignment.CENTER);
+
+        } else if (stringMatrix[1].equals("")) {
+
+            outputText.setText("Pease insert MatrixB");
+            outputText.setTextAlignment(TextAlignment.CENTER);
+        }
+
+    }
+}

src/main/java/com/ugsbo/matrixcalc/MatrixCalcIOUtils.java

@@ -0,0 +1,97 @@
+package com.ugsbo.matrixcalc;
+
+import java.util.ArrayList;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class MatrixCalcIOUtils {
+    /**
+     * Prints a given 2D-Array to the output Textfield.
+     * 
+     * @param output2DArray The Array that gets Displayed
+     */
+    protected String outputMatrixToOutputText(double[][] output2DArray) {
+        // convert array to String
+        String DisplayableString = convertsArrayToStringInOrderToDisplayIt(output2DArray);
+        // Display output
+        return DisplayableString;
+    }
+
+    /**
+     * Converts 2D-Array to String in order to Display it.
+     * 
+     * @param array2D The array wich will be converted to an Displayable String
+     * @return The Displayable String
+     */
+    protected String convertsArrayToStringInOrderToDisplayIt(double[][] array2D) {
+        String displayableString = "";
+        for (int i = 0; i < array2D.length; i++) {
+            for (int j = 0; j < array2D[0].length; j++) {
+                displayableString += array2D[i][j] + "   ";
+            }
+            displayableString += "\n\n";
+        }
+        return displayableString;
+    }
+
+    /**
+     * Checks if the Input is Valid, with Regex. Returns true if the Matrix can be
+     * matched by the regular Expression.
+     * 
+     * @param matrix It is the InputMatrix
+     * @return True if the Matrix is valid Input.
+     */
+    protected void checkInput(String matrix) throws IllegalArgumentException {
+        if (matrix.length() == 0) {
+            throw new IllegalArgumentException("Please insert a Matrix");
+        }
+
+        // Matches digits witch following spaces 1 to 3 times
+        String row1 = "(\\d*\\u0020*){1,3}";
+        // Matches newlineCurrierReturn followed by digits witch following spaces 1 to
+        // 3 times
+        String row2 = "(\\n){0,3}(\\d*\\u0020*){0,3}";
+        String row3 = "(\\n){0,3}(\\d*\\u0020*){0,3}";
+
+        // TODO for verion 2 get the input check more stricktly missing matrix slots are allowed.
+
+        Pattern p = Pattern.compile(row1 + row2 + row3);
+        Matcher m = p.matcher(matrix);
+        
+        if(!m.matches()){
+            throw new IllegalArgumentException("A Matrix is not in the right format, Matrix ");
+        }
+    }
+
+    /**
+     * Converts a String form the Inputfield to an 2D-Array aka Matrix.
+     * 
+     * @param stringMatrix The String form the Inputfield
+     * @return Matrix as a 2D-Array
+     */
+    public double[][] stringToMatrix(String stringMatrix) {
+
+        ArrayList<String[]> singleNumbersArr = new ArrayList<String[]>();
+
+        // Splitting the strings into their rows
+        String[] singleNumbers = null;
+        String[] rows = stringMatrix.split("\n");
+        for (int i = 0; i < rows.length; i++) {
+            // Splitting rows into their Numbers
+            singleNumbers = rows[i].split("\\s");
+            singleNumbersArr.add(singleNumbers);
+        }
+
+        int rowlength = singleNumbersArr.get(0).length;
+        int columCount = singleNumbersArr.size();
+        double[][] matrix = new double[columCount][rowlength];
+
+        for (int columIndex = 0; columIndex < columCount; columIndex++) {
+            for (int rowIndex = 0; rowIndex < singleNumbers.length; rowIndex++) {
+                matrix[columIndex][rowIndex] = Double.parseDouble(singleNumbersArr.get(columIndex)[rowIndex]);
+            }
+        }
+        return matrix;
+    }
+
+}

src/main/java/com/ugsbo/matrixcalc/MatrixCalcMath.java

@@ -0,0 +1,228 @@
+package com.ugsbo.matrixcalc;
+
+/**
+ * Contains all basic matrix math calculations.
+ */
+public class MatrixCalcMath {
+
+    /**
+     * Mutliplys matrixA and matrixB.
+     * 
+     * @param matrixA The Inputmatrix A (right TextArea in the GUI)
+     * @param matrixB The Inputmatrix B (left TextArea in the GUI)
+     * @return The Matrixproduct of the matricies A and B
+     */
+    public double[][] matrixMultiplication(double[][] matrixA, double[][] matrixB) {
+        if (checkIfMatriciesAreLinked(matrixA, matrixB)) {
+            int rowOfResultMatrix = matrixA.length;
+            int columOfResultMatrix = matrixB[0].length;
+            int ColumsOfMatA = matrixA[0].length;
+            double[][] result = new double[rowOfResultMatrix][columOfResultMatrix];
+
+            for (int rowResult = 0; rowResult < rowOfResultMatrix; rowResult++) {
+                for (int columResult = 0; columResult < columOfResultMatrix; columResult++) {
+                    for (int columOfA = 0; columOfA < ColumsOfMatA; columOfA++) {
+                        result[rowResult][columResult] += matrixA[rowResult][columOfA] * matrixB[columOfA][columResult];
+                    }
+                }
+            }
+            return result;
+        } else {
+            throw new IllegalArgumentException("Matricies must be linked");
+        }
+    }
+
+    /**
+     * checks if matrixA and matrixB are linked to know if it is possible to
+     * multiply them. If they are linked it is possible.
+     * 
+     * @param matrixA The Inputmatrix A (right TextArea in the GUI)
+     * @param matrixB The Inputmatrix B (left TextArea in the GUI)
+     * @return true if you can Muliply A with B false if not.
+     */
+    public boolean checkIfMatriciesAreLinked(double[][] matrixA, double[][] matrixB) {
+        if (matrixA == null) {
+            return false;
+        }
+        if (matrixA.length == 0) {
+            return false;
+        }
+        if (matrixA[0].length == matrixB.length) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Adds two matroices A and B. Adding matrix A to matrix B is the same as adding
+     * B to A.
+     * 
+     * @param matrixA The Inputmatrix A (right TextArea in the GUI)
+     * @param matrixB The Inputmatrix B (left TextArea in the GUI)
+     * @return The Matrixsum of matrix A and matrix B
+     */
+    public double[][] matrixAddition(double[][] matrixA, double[][] matrixB) {
+        if (checkIfMatriciesAreTheSameDimension(matrixA, matrixB)) {
+            double[][] result = new double[matrixA.length][matrixA[0].length];
+            for (int rows = 0; rows < matrixA.length; rows++) {
+                for (int colums = 0; colums < matrixA[0].length; colums++) {
+                    result[rows][colums] = matrixA[rows][colums] + matrixB[rows][colums];
+                }
+            }
+            return result;
+        } else {
+            throw new IllegalArgumentException("Matricies need to have the same Dimensions");
+        }
+    }
+
+    /**
+     * In order to adding two Matricies they must have the same Dimensions. This
+     * Methode checks if this is the case.
+     * 
+     * @param matrixA The Inputmatrix A (right TextArea in the GUI)
+     * @param matrixB The Inputmatrix B (left TextArea in the GUI)
+     * @return true if the Dimensions of Matrix A equals the Dimensions Matrix B
+     */
+    public boolean checkIfMatriciesAreTheSameDimension(double[][] matrixA, double[][] matrixB) {
+        if (matrixA == null || matrixA.length == 0) {
+            return false;
+        }
+        if (matrixA[0] == null) {
+            return false;
+        }
+        if (matrixA.length == matrixB.length && matrixA[0].length == matrixB[0].length) {
+            return true;
+        } else {
+            return false;
+        }
+
+    }
+
+    /**
+     * Substracts matrix A by the matrix B. Substaction for Matrices is just the
+     * substraction of each component with thier coorsponding component.
+     * 
+     * @param matrixA The Inputmatrix A (right TextArea in the GUI)
+     * @param matrixB The Inputmatrix B (left TextArea in the GUI
+     * @return matrix A substracted by matrix B
+     */
+    public double[][] matrixSubstraction(double[][] matrixA, double[][] matrixB) {
+        if (checkIfMatriciesAreTheSameDimension(matrixA, matrixB)) {
+            double[][] result = new double[matrixA.length][matrixA[0].length];
+            for (int rows = 0; rows < matrixA.length; rows++) {
+                for (int colums = 0; colums < matrixA[0].length; colums++) {
+                    result[rows][colums] = matrixA[rows][colums] - matrixB[rows][colums];
+                }
+            }
+            return result;
+        } else {
+            throw new IllegalArgumentException("Matricies need to have the same Dimensions");
+        }
+    }
+
+    /**
+     * Transposes the Input Matrix. Swaps rows with colums.
+     * 
+     * @param matrixA The Inputmatrix A wich will be Transposed
+     * @return The Transposed matrix of matrix A
+     */
+    public double[][] matrixTransponation(double[][] matrixA) {
+        if (matrixA == null) {
+            throw new IllegalArgumentException("Matricies need to have the same Dimensions");
+        }
+        if (matrixA.length == 0) {
+            throw new IllegalArgumentException("Matricies need to have the same Dimensions");
+        }
+        if (matrixA[0] == null) {
+            throw new IllegalArgumentException("Matricies need to have the same Dimensions");
+        }
+        int columCountResult = matrixA.length;
+        int rowCountResult = matrixA[0].length;
+        double[][] result = new double[rowCountResult][columCountResult];
+        for (int row = 0; row < rowCountResult; row++) {
+            for (int colum = 0; colum < columCountResult; colum++) {
+                result[row][colum] = matrixA[colum][row];
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Calculates the Determinant of a Matrix.
+     * 
+     * @param matrixA The Inputmatrix
+     * @return The Determinant of the Matrix A
+     */
+    public double calcDeterminat(double[][] matrixA) throws IllegalArgumentException{
+        // checking if a Determinant can be calculated.
+        double result = 0.0;
+        if (checkIfMatrixIsQuadradtic(matrixA)) {
+            if (getMatrixRowCount(matrixA) == 2) {
+                result = calc2by2Determinant(matrixA);
+            } else if (getMatrixRowCount(matrixA) == 3) {
+                result = calc3by3Determinant(matrixA);
+
+            } else {
+                throw new IllegalArgumentException("Matrix is not 2 by 2 or 3 by 3");
+            }
+
+        } else {
+            throw new IllegalArgumentException("Matrix must be Quadratic");
+        }
+        return result;
+    }
+
+    /**
+     * Calculates the Determinat of an three by three Matrix.
+     * 
+     * @param matrixA The Inputmatrix form wich the Determinat will be calculated
+     * @return the Determinant of the Matrix
+     */
+    private double calc3by3Determinant(double[][] matrixA) {
+        double result = matrixA[0][0] * matrixA[1][1] * matrixA[2][2] + matrixA[0][1] * matrixA[1][2] * matrixA[2][0]
+                + matrixA[0][2] * matrixA[1][0] * matrixA[2][1] - matrixA[0][0] * matrixA[1][2] * matrixA[2][1]
+                - matrixA[0][1] * matrixA[1][0] * matrixA[2][2] - matrixA[0][2] * matrixA[1][1] * matrixA[2][0];
+        return result;
+    }
+
+    /**
+     * Calculates the Determinat of an two by two Matrix.
+     * 
+     * @param matrixA The Inputmatrix form wich the Determinat will be calculated
+     * @return the Determinant of the Matrix
+     */
+    private double calc2by2Determinant(double[][] matrixA) {
+        double result = matrixA[0][0] * matrixA[1][1] - matrixA[0][1] * matrixA[1][0];
+        return result;
+    }
+
+    /**
+     * Returns the Number of rows of a Matrix.
+     * 
+     * @param matrixA the Inputmatrix form wich the rows will be counted
+     * @return Number of rows
+     */
+    private int getMatrixRowCount(double[][] matrixA) {
+        return matrixA.length;
+    }
+
+    /**
+     * Checks if the rows and colums of an Matrix are equal. If they are equal the
+     * Matrix is Quadratic and the function will return true.
+     * 
+     * @param matrixA the Inputmatrix for wich the rows and colums will be compared
+     * @return isQuadratic
+     */
+    private boolean checkIfMatrixIsQuadradtic(double[][] matrixA) {
+        if (matrixA == null) {
+            return false;
+        }
+        if (matrixA[0] == null) {
+            return false;
+        }
+        if (matrixA.length == matrixA[0].length) {
+            return true;
+        }
+        return false;
+    }
+}

src/main/resources/com/ugsbo/gui/BasicGui.fxml

@@ -27,8 +27,8 @@
       </AnchorPane>
     <AnchorPane maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" minHeight="-Infinity" minWidth="-Infinity" prefHeight="300.0" prefWidth="200.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="150.0" AnchorPane.rightAnchor="150.0" AnchorPane.topAnchor="50.0">
          <children>
-            <Button fx:id="app1" maxHeight="-Infinity" maxWidth="1.7976931348623157E308" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" prefHeight="30.0" prefWidth="260.0" text="ToDoListe" textAlignment="CENTER" AnchorPane.leftAnchor="19.0" AnchorPane.rightAnchor="19.0" AnchorPane.topAnchor="15.0" />
-            <Button fx:id="app2" maxHeight="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" prefHeight="30.0" prefWidth="260.0" text="VokabelKartenSchreiber" textAlignment="CENTER" AnchorPane.leftAnchor="19.0" AnchorPane.rightAnchor="19.0" AnchorPane.topAnchor="60.0" />
+            <Button fx:id="matrixCalc" maxHeight="-Infinity" maxWidth="1.7976931348623157E308" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" prefHeight="30.0" prefWidth="260.0" text="Matrix Calculator" textAlignment="CENTER" AnchorPane.leftAnchor="19.0" AnchorPane.rightAnchor="19.0" AnchorPane.topAnchor="15.0" />
+            <Button fx:id="app2" maxHeight="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" prefHeight="30.0" prefWidth="260.0" text="App2" textAlignment="CENTER" AnchorPane.leftAnchor="19.0" AnchorPane.rightAnchor="19.0" AnchorPane.topAnchor="60.0" />
             <Button fx:id="app3" maxHeight="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" prefHeight="30.0" prefWidth="260.0" text="App3" textAlignment="CENTER" AnchorPane.leftAnchor="19.0" AnchorPane.rightAnchor="19.0" AnchorPane.topAnchor="105.0" />
             <Button fx:id="app4" maxHeight="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" prefHeight="30.0" prefWidth="260.0" text="App4" textAlignment="CENTER" AnchorPane.leftAnchor="19.0" AnchorPane.rightAnchor="19.0" AnchorPane.topAnchor="150.0" />
          </children>

src/main/resources/com/ugsbo/gui/matrixCalcGui.fxml

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import java.lang.*?>
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+<?import javafx.scene.text.*?>
+<?import javafx.scene.control.Button?>
+<?import javafx.scene.control.TextArea?>
+<?import javafx.scene.layout.AnchorPane?>
+<?import javafx.scene.text.Text?>
+
+<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.ugsbo.matrixcalc.MatrixCalcController">
+   <children>
+      <AnchorPane prefHeight="200.0" prefWidth="200.0" AnchorPane.leftAnchor="0.0" AnchorPane.topAnchor="0.0">
+         <children>
+            <TextArea fx:id="matrixATextArea" prefHeight="200.0" prefWidth="200.0" AnchorPane.bottomAnchor="10.0" AnchorPane.leftAnchor="10.0" AnchorPane.rightAnchor="10.0" AnchorPane.topAnchor="10.0" />
+         </children>
+      </AnchorPane>
+      <AnchorPane layoutX="200.0" prefHeight="200.0" prefWidth="200.0" AnchorPane.bottomAnchor="200.0" AnchorPane.leftAnchor="200.0" AnchorPane.rightAnchor="200.0" AnchorPane.topAnchor="0.0">
+         <children>
+            <Button fx:id="multiplyButton" layoutX="14.0" layoutY="27.0" mnemonicParsing="false" text="multiply" AnchorPane.leftAnchor="15.0" AnchorPane.topAnchor="27.0" />
+            <Button fx:id="addButton" layoutX="14.0" layoutY="62.0" mnemonicParsing="false" text="add" AnchorPane.leftAnchor="15.0" AnchorPane.topAnchor="67.0" />
+            <Button fx:id="substractButton" layoutX="99.0" layoutY="62.0" mnemonicParsing="false" text="Substract" AnchorPane.rightAnchor="15.0" AnchorPane.topAnchor="67.0" />
+            <Button fx:id="transposeButton" layoutX="97.0" layoutY="27.0" mnemonicParsing="false" text="Transpose" AnchorPane.rightAnchor="15.0" AnchorPane.topAnchor="27.0" />
+            <Button fx:id="DetAButton" layoutX="14.0" layoutY="95.0" mnemonicParsing="false" text="DetA" AnchorPane.leftAnchor="15.0" AnchorPane.topAnchor="107.0" />
+            <Button fx:id="DetBButton" layoutX="120.0" layoutY="107.0" mnemonicParsing="false" text="DetB" />
+            <Text fx:id="errorText" layoutX="14.0" layoutY="113.0" strokeType="OUTSIDE" strokeWidth="0.0" AnchorPane.bottomAnchor="10.0" AnchorPane.leftAnchor="10.0" AnchorPane.rightAnchor="10.0" AnchorPane.topAnchor="100.0" />
+         </children>
+      </AnchorPane>
+      <AnchorPane layoutX="400.0" prefHeight="200.0" prefWidth="200.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
+         <children>
+            <TextArea fx:id="matrixBTextArea" layoutX="-15.0" layoutY="30.0" prefHeight="200.0" prefWidth="200.0" AnchorPane.bottomAnchor="10.0" AnchorPane.leftAnchor="10.0" AnchorPane.rightAnchor="10.0" AnchorPane.topAnchor="10.0" />
+         </children>
+      </AnchorPane>
+      <Text fx:id="outputText" layoutX="14.0" layoutY="242.0" strokeType="OUTSIDE" strokeWidth="0.0" textAlignment="JUSTIFY" wrappingWidth="554.7294921875" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="10.0" AnchorPane.rightAnchor="10.0" AnchorPane.topAnchor="210.0" />
+   </children>
+</AnchorPane>

src/test/java/com/ugsbo/matrixcalc/MatrixAdditionAndSubstractionTest.java

@@ -0,0 +1,156 @@
+package com.ugsbo.matrixcalc;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Tests the funktionality to add and substract two matricies
+ */
+public class MatrixAdditionAndSubstractionTest {
+
+    private MatrixCalcMath matrixMath;
+
+    @Before
+    public void setup() {
+        matrixMath = new MatrixCalcMath();
+    }
+
+    @Test
+    public void twoMatriciesHaveTheSameDimensions() {
+        double[][] matrixA = new double[1][1];
+        double[][] matrixB = new double[1][1];
+
+        boolean result = matrixMath.checkIfMatriciesAreTheSameDimension(matrixA, matrixB);
+
+        assertTrue("Two Matricies with the same Dimension were not detected as that", result);
+    }
+
+    @Test
+    public void twoMatriciesDONOTHaveTheSameDimensions() {
+        double[][] matrixA = new double[2][1];
+        double[][] matrixB = new double[1][1];
+
+        boolean result = matrixMath.checkIfMatriciesAreTheSameDimension(matrixA, matrixB);
+
+        assertFalse("Two Matricies without the same Dimension were detected as that", result);
+    }
+
+    @Test
+    public void addTwoMatriciesWithSameContent() {
+        double[][] matrixA = { { 1.0, 1.0 }, { 1.0, 1.0 } };
+        double[][] matrixB = { { 1.0, 1.0 }, { 1.0, 1.0 } };
+        double[][] matrixC = { { 2.0, 2.0 }, { 2.0, 2.0 } };
+
+        double[][] result = matrixMath.matrixAddition(matrixA, matrixB);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test
+    public void addTwoMatriciesWithDiffrentContent() {
+        double[][] matrixA = { { 7.0, 3.0 }, { 2.0, 9.0 } };
+        double[][] matrixB = { { 6.0, 3.0 }, { 7.0, 11.0 } };
+        double[][] matrixC = { { 13.0, 6.0 }, { 9.0, 20.0 } };
+
+        double[][] result = matrixMath.matrixAddition(matrixA, matrixB);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void tryToAddTowEmptyMatricies() {
+        // A(0,0) B(0,0) => IllegalArgumentException
+        double[][] matrixA = new double[0][0];
+        double[][] matrixB = new double[0][0];
+
+        matrixMath.matrixAddition(matrixA, matrixB);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void tryToAddTowNullMatrices() {
+        // A(0,0) B(0,0) => IllegalArgumentException
+        double[][] matrixA = null;
+        double[][] matrixB = null;
+
+        matrixMath.matrixAddition(matrixA, matrixB);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void tryToAddTowMatricesWithDifferentDimensions() {
+        // A(0,0) B(0,0) => IllegalArgumentException
+        double[][] matrixA = { { 1.0, 2.0 } };
+        double[][] matrixB = { { 1.0 }, { 2.0 } };
+
+        matrixMath.matrixAddition(matrixA, matrixB);
+    }
+
+    @Test
+    public void substractTwoMatriciesWithSameContent() {
+        double[][] matrixA = { { 1.0, 1.0 }, { 1.0, 1.0 } };
+        double[][] matrixB = { { 1.0, 1.0 }, { 1.0, 1.0 } };
+        double[][] matrixC = { { 0.0, 0.0 }, { 0.0, 0.0 } };
+
+        double[][] result = matrixMath.matrixSubstraction(matrixA, matrixB);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test
+    public void substractTwoMatriciesWithDiffrentContent() {
+        double[][] matrixA = { { 1.0, 2.0 }, { 3.0, 4.0 } };
+        double[][] matrixB = { { 5.0, 6.0 }, { 7.0, 8.0 } };
+        double[][] matrixC = { { -4.0, -4.0 }, { -4.0, -4.0 } };
+
+        double[][] result = matrixMath.matrixSubstraction(matrixA, matrixB);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test
+    public void substractTwoMatriciesWithNegativeContent() {
+        double[][] matrixA = { { -1.0, -2.0 }, { -3.0, -4.0 } };
+        double[][] matrixB = { { 5.0, 6.0 }, { 7.0, 8.0 } };
+        double[][] matrixC = { { -6.0, -8.0 }, { -10.0, -12.0 } };
+
+        double[][] result = matrixMath.matrixSubstraction(matrixA, matrixB);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void tryToSubstractTowEmptyMatricies() {
+        // A(0,0) B(0,0) => IllegalArgumentException
+        double[][] matrixA = new double[0][0];
+        double[][] matrixB = new double[0][0];
+
+        matrixMath.matrixSubstraction(matrixA, matrixB);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void tryToSubstractTowNullMatrices() {
+        // A(0,0) B(0,0) => IllegalArgumentException
+        double[][] matrixA = null;
+        double[][] matrixB = null;
+
+        matrixMath.matrixSubstraction(matrixA, matrixB);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void tryToSubstractTowMatricesWithDifferentDimensions() {
+        // A(0,0) B(0,0) => IllegalArgumentException
+        double[][] matrixA = { { 1.0, 2.0 } };
+        double[][] matrixB = { { 1.0 }, { 2.0 } };
+
+        matrixMath.matrixSubstraction(matrixA, matrixB);
+
+    }
+}

src/test/java/com/ugsbo/matrixcalc/MatrixCalcDeterminatTest.java

@@ -0,0 +1,61 @@
+package com.ugsbo.matrixcalc;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Tests the funktionality to Calculate the Determinant of a Matrix.
+ */
+public class MatrixCalcDeterminatTest {
+
+    private MatrixCalcMath matrixMath;
+
+    @Before
+    public void setup() {
+        matrixMath = new MatrixCalcMath();
+    }
+
+    @Test
+    public void CalculatesTheDeterminanteOfA2by2Matrix() {
+        // A(2,2)
+        double[][] matrixA = { { 1.0, 2.0 }, { 3.0, 4.0 } };
+        double determinat = -2.0;
+        double delta = 0.01;
+
+        double result = matrixMath.calcDeterminat(matrixA);
+
+        assertEquals("The Determinant is not as it should be", determinat, result, delta);
+    }
+
+    @Test
+    public void CalculatesTheDeterminanteOfA3by3Matrix() {
+        // A(3,3)
+        double[][] matrixA = { { 1.0, 2.0, 1.0 }, { 3.0, 4.0, 0.0 }, { 5.0, 6.0, 0.0 } };
+        double determinat = -2.0;
+        double delta = 0.01;
+
+        double result = matrixMath.calcDeterminat(matrixA);
+
+        assertEquals("The Determinant is not as it should be", determinat, result, delta);
+
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void tryToCalculateA4by4Matrix_ShouldResulInIllegalArgumentException() {
+        // A(4,4)
+        double[][] matrixA = { { 1.0, 2.0, 1.0, 0.0 }, { 3.0, 4.0, 0.0, 0.0 }, { 5.0, 6.0, 0.0, 0.0 },
+                { 5.0, 6.0, 0.0, 0.0 } };
+
+        matrixMath.calcDeterminat(matrixA);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void tryToCalculateANonQuadraticMatrix_SouldResulInIllegalArgumentException() {
+        // A(2,4)
+        double[][] matrixA = { { 5.0, 6.0, 0.0, 0.0 }, { 5.0, 6.0, 0.0, 0.0 } };
+
+        matrixMath.calcDeterminat(matrixA);
+    }
+}

src/test/java/com/ugsbo/matrixcalc/MatrixIOUtilsTest.java

@@ -0,0 +1,170 @@
+package com.ugsbo.matrixcalc;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Tests how well worng input can be determent.
+ */
+public class MatrixIOUtilsTest {
+
+    private MatrixCalcIOUtils util;
+
+    @Before
+    public void setup() {
+        util = new MatrixCalcIOUtils();
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void inputEmptySouldThrowAIllegalArgumentException() {
+        String input = "";
+
+        util.checkInput(input);
+    }
+
+    @Test
+    public void checkIfA1by3MatrixIsValidInput() {
+        String input = "1 2 3";
+
+        try {
+            // act
+            util.checkInput(input);
+
+            // assert
+            assertTrue("The 1 by 3 Matrix should be Matched as valid input.", true);
+        } catch (IllegalArgumentException e) {
+            assertFalse("The 1 by 3 Matrix should be Matched as valid input.", true);
+        }
+    }
+
+    @Test
+    public void checkIfA2by3MatrixIsValidInput() {
+        // arrange
+        String input = "1 2 3\n1 2 3";
+
+        try {
+            // act
+            util.checkInput(input);
+
+            // assert
+            assertTrue("The 2 by 3 Matrix should be Matched as valid input.", true);
+        } catch (IllegalArgumentException e) {
+            assertFalse("The 2 by 3 Matrix should be Matched as valid input.", true);
+        }
+    }
+
+    @Test
+    public void checkIfA3by3MatrixIsValidInput() {
+        String input = "1 2 3\n1 2 3\n1 2 3";
+
+        try {
+            util.checkInput(input);
+
+            assertTrue("The 3 by 3 Matrix should be Matched as valid input.", true);
+        } catch (IllegalArgumentException e) {
+            assertFalse("The 3 by 3 Matrix should be Matched as valid input.", true);
+        }
+
+    }
+
+    @Test
+    public void StringWithSingleDigitNumbersToMatrix_ReturnsEquivalentMatrix() {
+        String inputString = "1";
+        double[][] expected = { { 1.0 } };
+
+        double[][] result = util.stringToMatrix(inputString);
+
+        assertArrayEquals("The first row is not correct", expected[0], result[0], 0.1);
+    }
+
+    @Test
+    public void StringWithfourDigitNumbersToMatrix_ReturnsEquivalentMatrix() {
+        String inputString = "1 2\n3 4";
+        double[][] expected = { { 1.0, 2.0 }, { 3.0, 4.0 } };
+
+        double[][] result = util.stringToMatrix(inputString);
+
+        assertArrayEquals("The first row is not correct", expected[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", expected[1], result[1], 0.1);
+    }
+
+    @Test
+    public void StringWithSixDigitNumbersToMatrix_Returns1by6Matrix() {
+        String inputString = "1 2 3 4 5 6";
+        double[][] expected = { { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 } };
+
+        double[][] result = util.stringToMatrix(inputString);
+
+        assertArrayEquals("The first row is not correct", expected[0], result[0], 0.1);
+    }
+
+    @Test
+    public void StringWithSixDigitNumbersToMatrix_Returns2by3Matrix() {
+        String inputString = "1 2 3\n4 5 6";
+        double[][] expected = { { 1.0, 2.0, 3.0 }, { 4.0, 5.0, 6.0 } };
+
+        double[][] result = util.stringToMatrix(inputString);
+
+        assertArrayEquals("The first row is not correct", expected[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", expected[1], result[1], 0.1);
+    }
+
+    @Test
+    public void StringWithSixDigitNumbersToMatrix_Returns3by2Matrix() {
+        String inputString = "1 2\n3 4\n5 6";
+        double[][] expected = { { 1.0, 2.0 }, { 3.0, 4.0 }, { 5.0, 6.0 } };
+
+        double[][] result = util.stringToMatrix(inputString);
+
+        assertArrayEquals("The first row is not correct", expected[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", expected[1], result[1], 0.1);
+        assertArrayEquals("The therd row is not correct", expected[2], result[2], 0.1);
+    }
+
+    @Test
+    public void StringWithNineDigitNumbersToMatrix_Returns3by3Matrix() {
+        String inputString = "1 2 3\n4 5 6\n7 8 9";
+        double[][] expected = { { 1.0, 2.0, 3.0 }, { 4.0, 5.0, 6.0 }, { 7.0, 8.0, 9.0 } };
+
+        double[][] result = util.stringToMatrix(inputString);
+
+        assertArrayEquals("The first row is not correct", expected[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", expected[1], result[1], 0.1);
+        assertArrayEquals("The thierd row is not correct", expected[2], result[2], 0.1);
+    }
+
+    @Test
+    public void convertsArrayToString_SingleNumber() {
+        double[][] matrix = { { 1.0 } };
+        String expected = "1.0   \n\n";
+
+        String result = util.convertsArrayToStringInOrderToDisplayIt(matrix);
+
+        assertEquals("The Strings do not Match", expected, result);
+    }
+
+    @Test
+    public void convertsArrayToString_FourNumbersInARow() {
+        double[][] matrix = { { 1.0, 2.0, 3.0, 4.0 } };
+        String expected = "1.0   2.0   3.0   4.0   \n\n";
+
+        String result = util.convertsArrayToStringInOrderToDisplayIt(matrix);
+
+        assertEquals("The Strings do not Match", expected, result);
+    }
+
+    @Test
+    public void convertsArrayToString_FourNumbersInTwoRows() {
+        double[][] matrix = { { 1.0, 2.0 }, { 3.0, 4.0 } };
+        String expected = "1.0   2.0   \n\n3.0   4.0   \n\n";
+
+        String result = util.convertsArrayToStringInOrderToDisplayIt(matrix);
+
+        assertEquals("The Strings do not Match", expected, result);
+    }
+}

src/test/java/com/ugsbo/matrixcalc/MatrixMultiplicationTest.java

@@ -0,0 +1,109 @@
+package com.ugsbo.matrixcalc;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Testet die Matrix Multiplication funkionalität
+ */
+public class MatrixMultiplicationTest {
+
+    private MatrixCalcMath matrixMath;
+
+    @Before
+    public void setup() {
+        matrixMath = new MatrixCalcMath();
+    }
+
+    @Test
+    public void matrixAIsLinkedToMatrixBSouldBeTrue() {
+        double[][] matrixA = new double[1][2];
+        double[][] matrixB = new double[2][1];
+
+        boolean result = matrixMath.checkIfMatriciesAreLinked(matrixA, matrixB);
+
+        assertTrue("Matrix A is Linked to B but it is not detected that way", result);
+    }
+
+    @Test
+    public void matrixAAndMatrixBAreNullSouldReturnFalse() {
+        double[][] matrixA = null;
+        double[][] matrixB = null;
+
+        boolean result = matrixMath.checkIfMatriciesAreLinked(matrixA, matrixB);
+
+        assertFalse("Matrix A and B are null but detected as Linked", result);
+    }
+
+    @Test
+    public void matrixAAndMatrixBAreNotLinkedSouldReturnFalse() {
+        double[][] matrixA = new double[1][1];
+        double[][] matrixB = new double[2][1];
+
+        boolean result = matrixMath.checkIfMatriciesAreLinked(matrixA, matrixB);
+
+        assertFalse("Matrix A and B are not Linked but detected as Linked", result);
+    }
+
+    @Test
+    public void multiplyTwoMatriciesWithSameDimensionsAndSameContent() {
+        double[][] matrixA = { { 1.0, 1.0 }, { 1.0, 1.0 } };
+        double[][] matrixB = { { 1.0, 1.0 }, { 1.0, 1.0 } };
+        double[][] matrixC = { { 2.0, 2.0 }, { 2.0, 2.0 } };
+
+        double[][] result = matrixMath.matrixMultiplication(matrixA, matrixB);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test
+    public void multiplyTowMatriciesWithDiffrentDimensions() {
+        // A(2,3) B(3,2) => C(2,2)
+        double[][] matrixA = { { 1.0, 1.0, 1.0 }, { 1.0, 1.0, 1.0 } };
+        double[][] matrixB = { { 1.0, 1.0 }, { 1.0, 1.0 }, { 1.0, 1.0 } };
+        double[][] matrixC = { { 3.0, 3.0 }, { 3.0, 3.0 } };
+
+        double[][] result = matrixMath.matrixMultiplication(matrixA, matrixB);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test
+    public void multiplyTowMatriciesWithDiffrentDimensionsAndDiffentContent() {
+        // A(2,3) B(3,2) => C(2,2)
+        double[][] matrixA = { { 1.0, 2.0, 3.0 }, { 4.0, 5.0, 6.0 } };
+        double[][] matrixB = { { 7.0, 8.0 }, { 9.0, 10.0 }, { 11.0, 12.0 } };
+        double[][] matrixC = { { 58.0, 64.0 }, { 139.0, 154.0 } };
+
+        double[][] result = matrixMath.matrixMultiplication(matrixA, matrixB);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+
+    public void tryToMultiplyTowEmptyMatricies() {
+        // A(0,0) B(0,0) => IllegalArgumentException
+        double[][] matrixA = new double[0][0];
+        double[][] matrixB = new double[0][0];
+
+        matrixMath.matrixMultiplication(matrixA, matrixB);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+
+    public void tryToMultiplyTowNullObjects() {
+        // null null => IllegalArgumentException
+        double[][] matrixA = null;
+        double[][] matrixB = null;
+
+        matrixMath.matrixMultiplication(matrixA, matrixB);
+    }
+}

src/test/java/com/ugsbo/matrixcalc/MatrixTransposeTest.java

@@ -0,0 +1,57 @@
+package com.ugsbo.matrixcalc;
+
+import static org.junit.Assert.assertArrayEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Tests the funktionality to Transpose a Matix
+ */
+public class MatrixTransposeTest {
+
+    private MatrixCalcMath matrixMath;
+
+    @Before
+    public void setup() {
+        matrixMath = new MatrixCalcMath();
+    }
+
+    @Test
+    public void TransformQuadraticMatrixA_ResultsInQuadraticMatrixC() {
+        // A(2,2) => C(2,2)
+        double[][] matrixA = { { 1.0, 2.0 }, { 3.0, 4.0 } };
+        double[][] matrixC = { { 1.0, 3.0 }, { 2.0, 4.0 } };
+
+        double[][] result = matrixMath.matrixTransponation(matrixA);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+    }
+
+    @Test
+    public void Transform2by3MatrixA_ResultsIn3by2MatrixC() {
+        // A(2,3) => C(3,2)
+        double[][] matrixA = { { 1.0, 2.0, 3.0 }, { 4.0, 5.0, 6.0 } };
+        double[][] matrixC = { { 1.0, 4.0 }, { 2.0, 5.0 }, { 3.0, 6.0 } };
+
+        double[][] result = matrixMath.matrixTransponation(matrixA);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+        assertArrayEquals("The third row is not correct", matrixC[2], result[2], 0.1);
+    }
+
+    @Test
+    public void Transform1by3MatrixA_ResultsIn3by1MatrixC() {
+        // A(1,3) => C(1,3)
+        double[][] matrixA = { { 1.0, 2.0, 3.0 } };
+        double[][] matrixC = { { 1.0 }, { 2.0 }, { 3.0 } };
+
+        double[][] result = matrixMath.matrixTransponation(matrixA);
+
+        assertArrayEquals("The first row is not correct", matrixC[0], result[0], 0.1);
+        assertArrayEquals("The second row is not correct", matrixC[1], result[1], 0.1);
+        assertArrayEquals("The third row is not correct", matrixC[2], result[2], 0.1);
+    }
+}