* @param B
* @return matrix constructs from ATA and B
*/
private GeneralMatrix createAB(GeneralMatrix ATA, GeneralMatrix B) {
GeneralMatrix BT = B.clone();
BT.transpose();
GeneralMatrix AAB = new GeneralMatrix(ATA.getNumRow() + B.getNumRow(),
ATA.getNumCol() + BT.getNumCol());
ATA.copySubMatrix(0, 0, ATA.getNumRow(), ATA.getNumCol(), 0, 0, AAB);