org.ejml.dense.row.linsol.lu.LinearSolverLu_DDRM Maven / Gradle / Ivy
/*
* Copyright (c) 2009-2018, 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.linsol.lu;
import org.ejml.data.DMatrixRMaj;
import org.ejml.dense.row.decomposition.lu.LUDecompositionBase_DDRM;
/**
* For each column in the B matrix it makes a copy, which is then solved for and
* writen into X. By making a copy of the column cpu cache issues are reduced.
*
* @author Peter Abeles
*/
public class LinearSolverLu_DDRM extends LinearSolverLuBase_DDRM {
boolean doImprove = false;
public LinearSolverLu_DDRM(LUDecompositionBase_DDRM decomp) {
super(decomp);
}
public LinearSolverLu_DDRM(LUDecompositionBase_DDRM decomp, boolean doImprove) {
super(decomp);
this.doImprove = doImprove;
}
@Override
public void solve(DMatrixRMaj B, DMatrixRMaj X) {
if( B.numRows != numRows )
throw new IllegalArgumentException("Unexpected dimensions for X: X rows = "+X.numRows+" expected = "+numRows);
X.reshape(numCols,B.numCols);
int numCols = B.numCols;
double dataB[] = B.data;
double dataX[] = X.data;
double []vv = decomp._getVV();
// for( int j = 0; j < numCols; j++ ) {
// for( int i = 0; i < this.numCols; i++ ) vv[i] = dataB[i*numCols+j];
// decomp._solveVectorInternal(vv);
// for( int i = 0; i < this.numCols; i++ ) dataX[i*numCols+j] = vv[i];
// }
for( int j = 0; j < numCols; j++ ) {
int index = j;
for( int i = 0; i < this.numCols; i++ , index += numCols ) vv[i] = dataB[index];
decomp._solveVectorInternal(vv);
index = j;
for( int i = 0; i < this.numCols; i++ , index += numCols ) dataX[index] = vv[i];
}
if( doImprove ) {
improveSol(B,X);
}
}
}