formatiert

matrix.c

@@ -6,30 +6,121 @@
 
 Matrix createMatrix(unsigned int rows, unsigned int cols)
 {
-    
+    Matrix m = {NULL, 0, 0};
+
+    if (rows == 0 || cols == 0)
+        return m;
+
+    m.buffer = (MatrixType *)calloc(rows * cols, sizeof(MatrixType));
+    if (m.buffer == NULL)
+        return m;
+
+    m.rows = rows;
+    m.cols = cols;
+    return m;
 }
 
 void clearMatrix(Matrix *matrix)
 {
-    
+
+    if (matrix != NULL)
+    {
+        free(matrix->buffer);
+        matrix->buffer = NULL;
+        matrix->rows = 0;
+        matrix->cols = 0;
+    }
 }
 
 void setMatrixAt(MatrixType value, Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
+// Matrix matrix zu Matrix *matrix, empfehlung
 {
-    
+    if (rowIdx < matrix.rows && colIdx < matrix.cols && matrix.buffer != NULL)
+        matrix.buffer[rowIdx * matrix.cols + colIdx] = value;
 }
 
 MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
 {
-    
+    if (rowIdx >= matrix.rows || colIdx >= matrix.cols || matrix.buffer == NULL)
+        return 0; // Sicherheitscheck
+    return matrix.buffer[rowIdx * matrix.cols + colIdx];
 }
 
+// TODO: Funktionen implementieren
+
 Matrix add(const Matrix matrix1, const Matrix matrix2)
 {
-    
+    //  check, equal rows
+    // "Elementweise Addition": test, if two matrix has exact size
+    if (matrix1.rows == matrix2.rows && matrix1.cols == matrix2.cols)
+    {
+        Matrix result_add = createMatrix(matrix1.rows, matrix1.cols);
+        for (int r = 0; r < matrix1.rows; r++)
+        {
+            for (int c = 0; c < matrix1.cols; c++)
+            {
+                // first version: matrix_add[r][c] = matrix1[r][c] + matrix2[r][c]
+                MatrixType sum = getMatrixAt(matrix1, r, c) + getMatrixAt(matrix2, r, c);
+                setMatrixAt(sum, result_add, r, c);
+            }
+        }
+        return result_add;
+    }
+    // "Broadcasting": matrix1 has 1 collum
+    if (matrix1.rows == matrix2.rows && matrix1.cols == 1)
+    {
+        Matrix result_add = createMatrix(matrix1.rows, matrix2.cols);
+        for (int r = 0; r < matrix1.rows; r++)
+        {
+            for (int c = 0; c < matrix2.cols; c++)
+            {
+                MatrixType sum = getMatrixAt(matrix2, r, c) + getMatrixAt(matrix1, r, 0);
+                setMatrixAt(sum, result_add, r, c);
+            }
+        }
+        return result_add;
+    }
+    // "Broadcasting": matrix2 has 1 collum
+    if (matrix1.rows == matrix2.rows && matrix2.cols == 1)
+    {
+        Matrix result_add = createMatrix(matrix1.rows, matrix1.cols);
+        for (int r = 0; r < matrix1.rows; r++)
+        {
+            for (int c = 0; c < matrix1.cols; c++)
+            {
+                MatrixType sum = getMatrixAt(matrix1, r, c) + getMatrixAt(matrix2, r, 0);
+                setMatrixAt(sum, result_add, r, c);
+            }
+        }
+        return result_add;
+    }
+
+    return createMatrix(0, 0);
 }
 
 Matrix multiply(const Matrix matrix1, const Matrix matrix2)
 {
-    
+    // Needed: rows/Zeilen, collums/Spalten
+    MatrixType buffer_add;
+    // Probe ob Spalten1 = Zeilen2
+    if (matrix1.cols != matrix2.rows)
+        return createMatrix(0, 0);
+
+    Matrix result_mul = createMatrix(matrix1.rows, matrix2.cols); // ""
+
+    for (unsigned int index = 0; index < matrix1.rows; index++)
+    {
+        for (unsigned int shift = 0; shift < matrix2.cols; shift++)
+        {
+            buffer_add = 0;
+            for (unsigned int skalar = 0; skalar < matrix1.cols; skalar++)
+            {
+                // buffer_add += matrix1[index][skalar]*matrix2[skalar][shift];
+                buffer_add += getMatrixAt(matrix1, index, skalar) * getMatrixAt(matrix2, skalar, shift);
+            }
+            // matrix_mul[index][shift] = buffer_add;
+            setMatrixAt(buffer_add, result_mul, index, shift); // result als Pointer, also mit &result
+        }
+    }
+    return result_mul;
 }

matrix.h

@@ -6,6 +6,11 @@
 typedef float MatrixType;
 
 // TODO Matrixtyp definieren
+typedef struct {
+    MatrixType *buffer;
+    unsigned int rows;
+    unsigned int cols;
+} Matrix;
 
 
 Matrix createMatrix(unsigned int rows, unsigned int cols);