From 2e36dce14572f097c9f06accb3ab9087893e926d Mon Sep 17 00:00:00 2001
From: Christophe Geuzaine <cgeuzaine@ulg.ac.be>
Date: Mon, 26 Oct 2009 20:57:38 +0000
Subject: [PATCH] better slepc interface
---
Solver/eigenSolver.cpp | 67 +++++++++++++++++++++---------------------
Solver/eigenSolver.h | 7 +++--
2 files changed, 39 insertions(+), 35 deletions(-)
diff --git a/Solver/eigenSolver.cpp b/Solver/eigenSolver.cpp
index 64176c5764..ddfade0e24 100644
--- a/Solver/eigenSolver.cpp
+++ b/Solver/eigenSolver.cpp
@@ -22,7 +22,7 @@ eigenSolver::eigenSolver(dofManager<double, double> *manager, std::string A,
}
}
-void eigenSolver::solve()
+void eigenSolver::solve(int numEigenValues, std::string which)
{
if(!_A) return;
Mat A = _A->getMatrix();
@@ -33,41 +33,47 @@ void eigenSolver::solve()
PetscInt N, M;
_try(MatGetSize(A, &N, &M));
- // treatment of a generalized eigenvalue problem A x - \lambda B x = 0
+ // generalized eigenvalue problem A x - \lambda B x = 0
EPS eps;
_try(EPSCreate(PETSC_COMM_WORLD, &eps));
_try(EPSSetOperators(eps, A, B));
- // FIXME: check if hermitian (EPS_HEP or EPS_GHEP)
- //_try(EPSSetProblemType(eps, _B ? EPS_GNHEP : EPS_NHEP));
- _try(EPSSetProblemType(eps, _B ? EPS_GHEP : EPS_HEP));
-
- // set options
- //_try(EPSSetWhichEigenpairs(eps, EPS_LARGEST_MAGNITUDE));
- //_try(EPSSetWhichEigenpairs(eps, EPS_SMALLEST_REAL));
- _try(EPSSetTarget(eps, 0.)); // find eigenvalues close to given target
- PetscInt nev = 2; // number of eigenvalues to compute
- PetscInt mpd = nev; // max dim allowed for the projected problem
- PetscInt ncv = nev + mpd; // max dim of the subspace to be used by the solver
- _try(EPSSetDimensions(eps, nev, ncv, mpd));
- //_try(EPSSetType(eps, EPSPOWER));
-
- // override options at runtime, petsc-style
+ bool hermitian = false; // FIXME
+ if(hermitian)
+ _try(EPSSetProblemType(eps, _B ? EPS_GHEP : EPS_HEP));
+ else
+ _try(EPSSetProblemType(eps, _B ? EPS_GNHEP : EPS_NHEP));
+
+ // set some default options
+ _try(EPSSetDimensions(eps, 5, PETSC_DECIDE, PETSC_DECIDE));
+
+ // override these options at runtime, petsc-style
_try(EPSSetFromOptions(eps));
+ // force options specified directly as arguments
+ if(numEigenValues)
+ _try(EPSSetDimensions(eps, numEigenValues, PETSC_DECIDE, PETSC_DECIDE));
+ if(which == "smallest")
+ _try(EPSSetWhichEigenpairs(eps, EPS_SMALLEST_MAGNITUDE));
+ else if(which == "largest")
+ _try(EPSSetWhichEigenpairs(eps, EPS_LARGEST_MAGNITUDE));
+
// print info
const EPSType type;
_try(EPSGetType(eps, &type));
Msg::Info("SLEPc solution method: %s", type);
- _try(EPSGetDimensions(eps, &nev, &ncv, &mpd));
+ PetscInt nev;
+ _try(EPSGetDimensions(eps, &nev, PETSC_NULL, PETSC_NULL));
Msg::Info("SLEPc number of requested eigenvalues: %d", nev);
PetscReal tol;
PetscInt maxit;
_try(EPSGetTolerances(eps, &tol, &maxit));
Msg::Info("SLEPc stopping condition: tol=%g, maxit=%d", tol, maxit);
-
+
+ // solve
Msg::Info("SLEPc solving...");
_try(EPSSolve(eps));
+ // check convergence
int its;
_try(EPSGetIterationNumber(eps, &its));
EPSConvergedReason reason;
@@ -75,7 +81,7 @@ void eigenSolver::solve()
if(reason == EPS_CONVERGED_TOL)
Msg::Info("SLEPc converged in %d iterations", its);
else if(reason == EPS_DIVERGED_ITS)
- Msg::Error("SLEPc did not converge in %d iterations", its);
+ Msg::Error("SLEPc diverged after %d iterations", its);
else if(reason == EPS_DIVERGED_BREAKDOWN)
Msg::Error("SLEPc generic breakdown in method");
else if(reason == EPS_DIVERGED_NONSYMMETRIC)
@@ -86,20 +92,15 @@ void eigenSolver::solve()
_try(EPSGetConverged(eps, &nconv));
Msg::Info("SLEPc number of converged eigenpairs: %d", nconv);
- // if number of converged solutions is greated than requested
- // discarded surplus solutions
+ // ignore additional eigenvalues if we get more than what we asked
if(nconv > nev) nconv = nev;
- // if number of converged solutions is less than requested display
- // only converged solutions
- if(nconv < nev) nev = nconv;
Vec xr, xi;
_try(MatGetVecs(A, PETSC_NULL, &xr));
_try(MatGetVecs(A, PETSC_NULL, &xi));
Msg::Info(" Re[EigenValue] Im[EigenValue]"
" Relative error");
- for (int i = nconv - 1; i > nconv - nev - 1; i--){
- std::vector<std::complex<double> > ev(N);
+ for (int i = 0; i < nconv; i++){
PetscScalar kr, ki;
_try(EPSGetEigenpair(eps, i, &kr, &ki, xr, xi));
PetscReal error;
@@ -111,15 +112,15 @@ void eigenSolver::solve()
PetscReal re = kr;
PetscReal im = ki;
#endif
- // Output eigenvalues and relative error (= ||Ax - eig*Bx||/||eig*x||)
- Msg::Info("EIG %03d %s%.16e %s%.16e %3.6e", (nconv - i),
- (re < 0) ? "" : " ", re, (im < 0) ? "" : " ", im, error);
- _eigenValues.push_back(std::complex<double>(re, im));
+ Msg::Info("EIG %03d %s%.16e %s%.16e %3.6e",
+ i, (re < 0) ? "" : " ", re, (im < 0) ? "" : " ", im, error);
- // Output eigenvector
+ // store eigenvalues and eigenvectors
+ _eigenValues.push_back(std::complex<double>(re, im));
PetscScalar *tmpr, *tmpi;
_try(VecGetArray(xr, &tmpr));
_try(VecGetArray(xi, &tmpi));
+ std::vector<std::complex<double> > ev(N);
for(int i = 0; i < N; i++){
#if defined(PETSC_USE_COMPLEX)
ev[i] = tmpr[i];
@@ -130,7 +131,7 @@ void eigenSolver::solve()
_eigenVectors.push_back(ev);
}
- // Free work space
+ // cleanup
_try(EPSDestroy(eps));
_try(VecDestroy(xr));
_try(VecDestroy(xi));
diff --git a/Solver/eigenSolver.h b/Solver/eigenSolver.h
index 709cd60b06..3fffcaf6f4 100644
--- a/Solver/eigenSolver.h
+++ b/Solver/eigenSolver.h
@@ -26,7 +26,7 @@ class eigenSolver{
public:
eigenSolver(dofManager<double, double> *manager, std::string A,
std::string B="");
- void solve();
+ void solve(int numEigenValues=0, std::string which="");
int getNumEigenValues(){ return _eigenValues.size(); }
std::complex<double> getEigenValue(int num){ return _eigenValues[num]; }
std::vector<std::complex<double> > &getEigenVector(int num){ return _eigenVectors[num]; }
@@ -40,7 +40,10 @@ class eigenSolver{
public:
eigenSolver(dofManager<double, double> *manager, std::string A,
std::string B=""){}
- void solve(){ Msg::Error("Eigen solver requires SLEPc"); }
+ void solve(int numEigenValues=0, std::string which="")
+ {
+ Msg::Error("Eigen solver requires SLEPc");
+ }
int getNumEigenValues(){ return 0.; }
std::complex<double> getEigenValue(int num){ return 0.; }
std::vector<std::complex<double> > &getEigenVector(int num){ return _dummy; }
--
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