org.ejml.dense.row.decomposition.hessenberg.TridiagonalDecomposition_DDRB_to_DDRM Maven / Gradle / Ivy
/*
* Copyright (c) 2009-2017, Peter Abeles. All Rights Reserved.
*
* This file is part of Efficient Java Matrix Library (EJML).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.ejml.dense.row.decomposition.hessenberg;
import org.ejml.EjmlParameters;
import org.ejml.data.DMatrixRBlock;
import org.ejml.data.DMatrixRMaj;
import org.ejml.dense.block.decomposition.hessenberg.TridiagonalDecompositionHouseholder_DDRB;
import org.ejml.dense.row.CommonOps_DDRM;
import org.ejml.dense.row.decomposition.BaseDecomposition_DDRB_to_DDRM;
import org.ejml.interfaces.decomposition.TridiagonalSimilarDecomposition_F64;
/**
* Wrapper around a block implementation of TridiagonalSimilarDecomposition_F64
*
* @author Peter Abeles
*/
public class TridiagonalDecomposition_DDRB_to_DDRM
extends BaseDecomposition_DDRB_to_DDRM
implements TridiagonalSimilarDecomposition_F64 {
public TridiagonalDecomposition_DDRB_to_DDRM() {
this(EjmlParameters.BLOCK_WIDTH);
}
public TridiagonalDecomposition_DDRB_to_DDRM(int blockSize) {
super(new TridiagonalDecompositionHouseholder_DDRB(),blockSize);
}
@Override
public DMatrixRMaj getT(DMatrixRMaj T) {
int N = Ablock.numRows;
if( T == null ) {
T = new DMatrixRMaj(N,N);
} else {
CommonOps_DDRM.fill(T, 0);
}
double[] diag = new double[ N ];
double[] off = new double[ N ];
((TridiagonalDecompositionHouseholder_DDRB)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 DMatrixRMaj getQ(DMatrixRMaj Q, boolean transposed) {
if( Q == null ) {
Q = new DMatrixRMaj(Ablock.numRows,Ablock.numCols);
}
DMatrixRBlock Qblock = new DMatrixRBlock();
Qblock.numRows = Q.numRows;
Qblock.numCols = Q.numCols;
Qblock.blockLength = blockLength;
Qblock.data = Q.data;
((TridiagonalDecompositionHouseholder_DDRB)alg).getQ(Qblock,transposed);
convertBlockToRow(Q.numRows,Q.numCols,Ablock.blockLength,Q.data);
return Q;
}
@Override
public void getDiagonal(double[] diag, double[] off) {
((TridiagonalDecompositionHouseholder_DDRB)alg).getDiagonal(diag,off);
}
}