Einfache Routine zur Matrix-Multiplikation

public static Matrix matmult(Matrix a, Matrix b) {
  // einfache Matrix-Multiplikation, ohne Checks
 
  int m = a.getColumnDimension();   
  int l = a.getRowDimension();  
  int n = b.getRowDimension();  
  Matrix c = new Matrix(n, m); 
  
  for (int i = 0; i < m; i++) {  
    for (int j = 0; j < n; j++) { 
      c.arr[i][j] = 0.0; 
      for (int k = 0; k < l; k++) { 
        c.arr[i][j] += a.arr[i][k] * b.arr[k][j];    
      } 
    }
  }  
  return c; 
}