diff --git a/makefile b/makefile
index f27b756..67a3c53 100644
--- a/makefile
+++ b/makefile
@@ -57,10 +57,11 @@ imageInputTests: imageInput.o imageInputTests.c $(unityfolder)/unity.c
 # --------------------------
 # Clean
 # --------------------------
+#clean:
+#ifeq ($(OS),Windows_NT)
+#	del /f *.o *.exe
+#else
+#	rm -f *.o mnist runMatrixTests runNeuralNetworkTests runImageInputTests
+#endif
 clean:
-ifeq ($(OS),Windows_NT)
-	del /f *.o *.exe
-else
-	rm -f *.o mnist runMatrixTests runNeuralNetworkTests runImageInputTests
-endif
-
+	rm -f *.o *.exe
\ No newline at end of file
diff --git a/matrix.c b/matrix.c
index f1a06f3..6cd833e 100644
--- a/matrix.c
+++ b/matrix.c
@@ -1,36 +1,38 @@
+#include "matrix.h"
 #include <stdlib.h>
 #include <string.h>
-#include "matrix.h"
-
 // TODO Matrix-Funktionen implementieren
-
-Matrix createMatrix(unsigned int rows, unsigned int cols)
-{
-    MatrixType* data = malloc(rows * cols * sizeof(MatrixType));
-    Matrix newMatrix = {rows, cols, data};
-    return newMatrix; 
+/*typedef struct {
+    unsigned int rows;  //Zeilen
+    unsigned int cols; //Spalten
+    MatrixType *data; //Zeiger auf Speicherbereich Reihen*Spalten
+} Matrix;*/
+Matrix createMatrix(unsigned int rows, unsigned int cols) {
+  MatrixType *data =
+      malloc(rows * cols * sizeof(MatrixType)); // Speicher reservieren, malloc
+                                                // liefert Zeiger auf Speicher
+  Matrix newMatrix = {rows, cols, data};        // neue Matrix nach struct
+  return newMatrix;
 }
-
-void clearMatrix(Matrix *matrix)
-{
+void clearMatrix(Matrix *matrix) {
+  matrix->data = UNDEFINED_MATRIX_VALUE;
+  matrix->rows = UNDEFINED_MATRIX_VALUE;
+  matrix->cols = UNDEFINED_MATRIX_VALUE;
+  free((*matrix).data); // Speicher freigeben
 }
-
-void setMatrixAt(MatrixType value, Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
-{
-    
+void setMatrixAt(MatrixType value, Matrix matrix,
+                 unsigned int rowIdx, // Kopie der Matrix wird übergeben
+                 unsigned int colIdx) {
+  matrix.data[rowIdx * matrix.cols + colIdx] =
+      value; // rowIdx * matrix.cols -> Beginn der Zeile colIdx ->Spalte
+             // innerhalb der Zeile
 }
-
-MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
-{
-    
+MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx,
+                       unsigned int colIdx) {
+  return 0;
 }
-
-Matrix add(const Matrix matrix1, const Matrix matrix2)
-{
-    
+Matrix add(const Matrix matrix1, const Matrix matrix2) {
+  // broadcasting
+  return matrix1;
 }
-
-Matrix multiply(const Matrix matrix1, const Matrix matrix2)
-{
-    
-}
\ No newline at end of file
+Matrix multiply(const Matrix matrix1, const Matrix matrix2) { return matrix1; }
diff --git a/matrix.h b/matrix.h
index 736e6e1..1d37962 100644
--- a/matrix.h
+++ b/matrix.h
@@ -6,20 +6,20 @@
 typedef float MatrixType;
 
 // TODO Matrixtyp definieren
-typedef struct
-{
-    unsigned int rows;
-    unsigned int cols;
-    MatrixType *data;
-} Matrix;
+typedef struct {
+  unsigned int rows;
+  unsigned int cols;
+  MatrixType *data;
 
+} Matrix;
 
 Matrix createMatrix(unsigned int rows, unsigned int cols);
 void clearMatrix(Matrix *matrix);
-void setMatrixAt(MatrixType value, Matrix matrix, unsigned int rowIdx, unsigned int colIdx);
-MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx, unsigned int colIdx);
+void setMatrixAt(MatrixType value, Matrix matrix, unsigned int rowIdx,
+                 unsigned int colIdx);
+MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx,
+                       unsigned int colIdx);
 Matrix add(const Matrix matrix1, const Matrix matrix2);
 Matrix multiply(const Matrix matrix1, const Matrix matrix2);
 
-
 #endif