/*
* 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.decomposition.hessenberg;
import org.ejml.EjmlParameters;
import org.ejml.alg.block.decomposition.hessenberg.TridiagonalDecompositionBlockHouseholder;
import org.ejml.alg.dense.decomposition.BaseDecompositionBlock64;
import org.ejml.data.BlockMatrix64F;
import org.ejml.data.DenseMatrix64F;
import org.ejml.ops.CommonOps;
/**
* Wrapper around a block implementation of TridiagonalSimilarDecomposition
*
* @author Peter Abeles
*/
public class TridiagonalDecompositionBlock
extends BaseDecompositionBlock64
implements TridiagonalSimilarDecomposition<DenseMatrix64F> {
public TridiagonalDecompositionBlock() {
this(EjmlParameters.BLOCK_WIDTH);
}
public TridiagonalDecompositionBlock( int blockSize ) {
super(new TridiagonalDecompositionBlockHouseholder(),blockSize);
}
@Override
public DenseMatrix64F getT(DenseMatrix64F T) {
int N = Ablock.numRows;
if( T == null ) {
T = new DenseMatrix64F(N,N);
} else {
CommonOps.fill(T, 0);
}
double[] diag = new double[ N ];
double[] off = new double[ N ];
((TridiagonalDecompositionBlockHouseholder)alg).getDiagonal(diag,off);
T.unsafe_set(0,0,diag[0]);
for( int i = 1; i < N; i++ ) {
T.unsafe_set(i,i,diag[i]);
T.unsafe_set(i,i-1,off[i-1]);
T.unsafe_set(i-1,i,off[i-1]);
}
return T;
}
@Override
public DenseMatrix64F getQ(DenseMatrix64F Q, boolean transposed) {
if( Q == null ) {
Q = new DenseMatrix64F(Ablock.numRows,Ablock.numCols);
}
BlockMatrix64F Qblock = new BlockMatrix64F();
Qblock.numRows = Q.numRows;
Qblock.numCols = Q.numCols;
Qblock.blockLength = blockLength;
Qblock.data = Q.data;
((TridiagonalDecompositionBlockHouseholder)alg).getQ(Qblock,transposed);
convertBlockToRow(Q.numRows,Q.numCols,Ablock.blockLength,Q.data);
return Q;
}
@Override
public void getDiagonal(double[] diag, double[] off) {
((TridiagonalDecompositionBlockHouseholder)alg).getDiagonal(diag,off);
}
}