NewtonKrylov.java
/**
* Copyright (c) 2023, RTE (http://www.rte-france.com)
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
* SPDX-License-Identifier: MPL-2.0
*/
package com.powsybl.openloadflow.ac.solver;
import com.powsybl.commons.report.ReportNode;
import com.powsybl.math.matrix.SparseMatrix;
import com.powsybl.math.solver.Kinsol;
import com.powsybl.math.solver.KinsolParameters;
import com.powsybl.math.solver.KinsolResult;
import com.powsybl.math.solver.KinsolStatus;
import com.powsybl.openloadflow.ac.equations.AcEquationType;
import com.powsybl.openloadflow.ac.equations.AcVariableType;
import com.powsybl.openloadflow.equations.EquationSystem;
import com.powsybl.openloadflow.equations.EquationVector;
import com.powsybl.openloadflow.equations.JacobianMatrix;
import com.powsybl.openloadflow.equations.TargetVector;
import com.powsybl.openloadflow.network.LfNetwork;
import com.powsybl.openloadflow.network.util.VoltageInitializer;
import java.util.Objects;
/**
* @author Geoffroy Jamgotchian {@literal <geoffroy.jamgotchian at rte-france.com>}
*/
public class NewtonKrylov extends AbstractAcSolver {
private final NewtonKrylovParameters parameters;
public NewtonKrylov(LfNetwork network, NewtonKrylovParameters parameters,
EquationSystem<AcVariableType, AcEquationType> equationSystem,
JacobianMatrix<AcVariableType, AcEquationType> j, TargetVector<AcVariableType, AcEquationType> targetVector,
EquationVector<AcVariableType, AcEquationType> equationVector) {
super(network, equationSystem, j, targetVector, equationVector, false);
this.parameters = Objects.requireNonNull(parameters);
}
@Override
public String getName() {
return "Newton Krylov";
}
private AcSolverStatus getStatus(KinsolStatus status) {
return switch (status) {
case KIN_SUCCESS, KIN_INITIAL_GUESS_OK -> AcSolverStatus.CONVERGED;
case KIN_MAXITER_REACHED -> AcSolverStatus.MAX_ITERATION_REACHED;
default -> AcSolverStatus.SOLVER_FAILED;
};
}
@Override
public AcSolverResult run(VoltageInitializer voltageInitializer, ReportNode reportNode) {
// initialize state vector
AcSolverUtil.initStateVector(network, equationSystem, voltageInitializer);
KinsolParameters kinsolParameters = new KinsolParameters()
.setMaxIters(parameters.getMaxIterations())
.setLineSearch(parameters.isLineSearch());
Kinsol kinsol = new Kinsol((SparseMatrix) j.getMatrix(), (x, f) -> {
equationSystem.getStateVector().set(x);
equationVector.minus(targetVector);
System.arraycopy(equationVector.getArray(), 0, f, 0, equationVector.getArray().length);
}, (x, j) -> {
// force jacobian values update because on C side we directly get access to internal data structure which
// does not update with last state vector
NewtonKrylov.this.j.forceUpdate();
});
KinsolResult result = kinsol.solveTransposed(equationSystem.getStateVector().get(), kinsolParameters);
if (result.getStatus() == KinsolStatus.KIN_SUCCESS) {
AcSolverUtil.updateNetwork(network, equationSystem);
}
return new AcSolverResult(getStatus(result.getStatus()), (int) result.getIterations(), 0);
}
}