// ******************************************************************* // Last Revised: September 1, 1997 // // APCS matrix class IMPLEMENTATION // // see matrix.h for complete documentation of functions // // extends vector class to two-dimensional matrices // ******************************************************************* #include "tmatrix.h" #include #include using namespace std; template tmatrix::tmatrix() : myRows(0), myCols(0), myMatrix(0) // postcondition: matrix of size 0x0 is constructed, and therefore // will need to be resized later { } template tmatrix::tmatrix(int rows,int cols) : myRows(rows), myCols(cols), myMatrix(rows) // precondition: 0 <= rows and 0 <= cols // postcondition: matrix of size rows x cols is constructed { int k; for(k=0; k < rows; k++) { myMatrix[k].resize(cols); } } template tmatrix::tmatrix(int rows, int cols, const itemType & fillValue) : myRows(rows), myCols(cols), myMatrix(rows) // precondition: 0 <= rows and 0 <= cols // postcondition: matrix of size rows x cols is constructed // all entries are set by assignment to fillValue after // default construction // { int j,k; for(j=0; j < rows; j++) { myMatrix[j].resize(cols); for(k=0; k < cols; k++) { myMatrix[j][k] = fillValue; } } } template tmatrix::tmatrix(const tmatrix & mat) : myRows(mat.myRows), myCols(mat.myCols), myMatrix(mat.myRows) // postcondition: matrix is a copy of mat { int k; // copy elements for(k = 0; k < myRows; k++) { // cast to avoid const problems (const -> non-const) myMatrix[k] = (tvector &) mat.myMatrix[k]; } } template tmatrix::~tmatrix () // postcondition: matrix is destroyed { // vector destructor frees everything } template const tmatrix & tmatrix::operator = (const tmatrix & rhs) // postcondition: normal assignment via copying has been performed // (if matrix and rhs were different sizes, matrix has // been resized to match the size of rhs) { if (this != &rhs) // don't assign to self! { myMatrix.resize(rhs.myRows); // resize to proper # of rows myRows = rhs.myRows; // set dimensions myCols = rhs.myCols; // copy rhs int k; for(k=0; k < myRows; k++) { myMatrix[k] = rhs.myMatrix[k]; } } return *this; } template int tmatrix::numrows() const // postcondition: returns number of rows { return myRows; } template int tmatrix::numcols() const // postcondition: returns number of columns { return myCols; } template void tmatrix::resize(int newRows, int newCols) // precondition: matrix size is rows X cols, // 0 <= newRows and 0 <= newCols // postcondition: matrix size is newRows X newCols; // for each 0 <= j <= min(rows,newRows) and // for each 0 <= k <= min(cols,newCols), matrix[j][k] is // a copy of the original; other elements of matrix are // initialized using the default constructor for itemType // Note: if newRows < rows or newCols < cols, // elements may be lost // { int k; myMatrix.resize(newRows); for(k=0; k < newRows; k++) { myMatrix[k].resize(newCols); } myRows = newRows; myCols = newCols; } template const tvector & tmatrix::operator [] (int k) const // precondition: 0 <= k < number of rows // postcondition: returns k-th row { if (k < 0 || myRows <= k) { cerr << "Illegal matrix index: " << k << " max index = "; cerr << myRows-1 << endl; exit(1); } return myMatrix[k]; } template tvector & tmatrix::operator [] (int k) // precondition: 0 <= k < number of rows // postcondition: returns k-th row { if (k < 0 || myRows <= k) { cerr << "Illegal matrix index: " << k << " max index = "; cerr << myRows-1 << endl; exit(1); } return myMatrix[k]; }