/*
* Copyright (c) 2009-2012, Peter Abeles. All Rights Reserved.
*
* This file is part of Efficient Java Matrix Library (EJML).
*
* EJML is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* EJML is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with EJML. If not, see <http://www.gnu.org/licenses/>.
*/
package org.ejml.alg.dense.linsol.qr;
import org.ejml.alg.dense.decomposition.qr.QRDecompositionHouseholderColumn;
import org.ejml.alg.dense.decomposition.qr.QrUpdate;
import org.ejml.alg.dense.linsol.AdjustableLinearSolver;
import org.ejml.data.DenseMatrix64F;
import org.ejml.ops.CommonOps;
/**
* A solver for QR decomposition that can efficiently modify the previous decomposition when
* data is added or removed.
*
* @author Peter Abeles
*/
public class AdjLinearSolverQr extends LinearSolverQr implements AdjustableLinearSolver {
private QrUpdate update;
private DenseMatrix64F A;
public AdjLinearSolverQr() {
super( new QRDecompositionHouseholderColumn() );
}
@Override
public void setMaxSize( int maxRows , int maxCols ) {
// allow it some room to grow
maxRows += 5;
super.setMaxSize(maxRows,maxCols);
update = new QrUpdate(maxRows,maxCols,true);
A = new DenseMatrix64F(maxRows,maxCols);
}
/**
* Compute the A matrix from the Q and R matrices.
*
* @return The A matrix.
*/
@Override
public DenseMatrix64F getA() {
if( A.data.length < numRows*numCols ) {
A = new DenseMatrix64F(numRows,numCols);
}
A.reshape(numRows,numCols, false);
CommonOps.mult(Q,R,A);
return A;
}
@Override
public boolean addRowToA(double[] A_row , int rowIndex ) {
// see if it needs to grow the data structures
if( numRows + 1 > maxRows) {
// grow by 10%
int grow = maxRows / 10;
if( grow < 1 ) grow = 1;
maxRows = numRows + grow;
Q.reshape(maxRows,maxRows,true);
R.reshape(maxRows,maxCols,true);
}
update.addRow(Q,R,A_row,rowIndex,true);
numRows++;
return true;
}
@Override
public boolean removeRowFromA(int index) {
update.deleteRow(Q,R,index,true);
numRows--;
return true;
}
}