Merge branch '74-switch-to-ovlp_amg_4_dg-for-all-computations' into 'master'

Resolve "Switch to OVLP_AMG_4_DG for all computations"

Closes #74

See merge request !61

CHANGELOG.md

@@ -15,12 +15,15 @@
 * Switch VTK output from conforming to non-conforming
 * Use `multicore` build tag only for `test:parallel` build because the current
     GitLab Runner cannot handle the load
+* Use the `OVLP_AMG_4_DG` linear solver for all computations, including
+    sequential ones. This significantly improves performance for large problems.
 
 ### Fixed
 * The source code is now compatible to the Clang LLVM compiler.
     DORiE can now be compiled with the onboard compiler on macOS.
 * Fix finite element map used for simplex grids. The old one did not implement
     a discontinuous function space.
+* Allow warnings on ParMETIS not being available for parallel computations.
 
 
 ## 1.0.0 (2018-03-28)

dune/dorie/interface/simulation.cc

@@ -77,44 +77,23 @@ void Simulation<Traits>::operator_setup ()
 	go1 = std::make_unique<GO1>(*gfs,*cc,*gfs,*cc,*tlop,mbe_tlop);
 	igo = std::make_unique<IGO>(*go0,*go1);
 
-	// build parallel solvers
-	if (helper.size() > 1) {
-		// --- Solvers ---
-		lsgfs = std::make_unique<LSGFS>(LSGFSHelper::create(gv));
-		lscc = std::make_unique<LSCC>();
-		ls_par = std::make_unique<LSPar>(*igo,*cc,*lsgfs,*lscc,1000,0,true,true);
-
-		pdesolver_par = std::make_unique<PDESOLVERPar>(*igo,*ls_par);
-		pdesolver_par->setParameters(inifile.sub("NewtonParameters"));
-		pdesolver_par->setVerbosityLevel(verbose);
-
-		// --- Time Step Operators ---
-		Dune::PDELab::OneStepMethodResult osm_result;
-		if(osm_par){
-			osm_result = osm_par->result(); // cache old result
-		}
-		osm_par = std::make_unique<OSMPar>(alex2,*igo,*pdesolver_par);
-		osm_par->setResult(osm_result);
-		osm_par->setVerbosityLevel(verbose+1);
-	}
-
-	// build sequential solvers
-	else {
-		ls_seq = std::make_unique<LSSeq>(5000,0);
-
-		pdesolver_seq = std::make_unique<PDESOLVERSeq>(*igo,*ls_seq);
-		pdesolver_seq->setParameters(inifile.sub("NewtonParameters"));
-		pdesolver_seq->setVerbosityLevel(verbose);
-
-		// --- Time Step Operators ---
-		Dune::PDELab::OneStepMethodResult osm_result;
-		if(osm_seq){
-			osm_result = osm_seq->result(); // cache old result
-		}
-		osm_seq = std::make_unique<OSMSeq>(alex2,*igo,*pdesolver_seq);
-		osm_seq->setResult(osm_result);
-		osm_seq->setVerbosityLevel(verbose+1);
+	// --- Solvers ---
+	lsgfs = std::make_unique<LSGFS>(LSGFSHelper::create(gv));
+	lscc = std::make_unique<LSCC>();
+	ls = std::make_unique<LS>(*igo,*cc,*lsgfs,*lscc,1000,0,true,true);
+
+	pdesolver = std::make_unique<PDESOLVER>(*igo,*ls);
+	pdesolver->setParameters(inifile.sub("NewtonParameters"));
+	pdesolver->setVerbosityLevel(verbose);
+
+	// --- Time Step Operators ---
+	Dune::PDELab::OneStepMethodResult osm_result;
+	if(osm){
+		osm_result = osm->result(); // cache old result
 	}
+	osm = std::make_unique<OSM>(alex2,*igo,*pdesolver);
+	osm->setResult(osm_result);
+	osm->setVerbosityLevel(verbose+1);
 
 	gfs->update();
 
@@ -141,21 +120,18 @@ bool Simulation<Traits>::compute_time_step ()
 	const RF t = controller->getTime();
 	const RF dt = controller->getDT();
 	bool exception = false;
+	const bool parmetis_warning = verbose > 0 && helper.rank() == 0 ?
+		true : false;
 
 	try
 	{
-		// solve in parallel
-		if (helper.size() > 1) {
-			pdesolver_par->setMaxIterations(controller->getIterations());
+		pdesolver->setMaxIterations(controller->getIterations());
+
+		if (not parmetis_warning)
 			dwarn.push(false);
-			osm_par->apply(t,dt,*uold,*unew);
+		osm->apply(t, dt, *uold, *unew);
+		if (not parmetis_warning)
 			dwarn.pop();
-		}
-		// solve sequentially
-		else {
-			pdesolver_seq->setMaxIterations(controller->getIterations());
-			osm_seq->apply(t, dt, *uold, *unew);
-		}
 
 		*uold = *unew;
 	}

dune/dorie/interface/simulation.hh

@@ -65,17 +65,14 @@ protected:
 	/// Solution vector type
 	using U = typename IGO::Traits::Domain;
 	/// Linear solver types
-	using LSSeq = Dune::PDELab::ISTLBackend_SEQ_SuperLU;
-	using LSPar = Dune::PDELab::ISTLBackend_OVLP_AMG_4_DG<IGO,CC,LSGFS,LSCC,
+	using LS = Dune::PDELab::ISTLBackend_OVLP_AMG_4_DG<IGO,CC,LSGFS,LSCC,
 		Dune::PDELab::CG2DGProlongation,Dune::SeqSSOR,Dune::BiCGSTABSolver>;
 	/// Non-linear solver types
-	using PDESOLVERSeq = Dune::PDELab::Newton<IGO,LSSeq,U>;
-	using PDESOLVERPar = Dune::PDELab::Newton<IGO,LSPar,U>;
+	using PDESOLVER = Dune::PDELab::Newton<IGO,LS,U>;
 	/// Time stepping scheme
 	using TimeStepScheme = Dune::PDELab::Alexander2Parameter<RF>;
 	/// Methods computing the time step
-	using OSMSeq = Dune::PDELab::OneStepMethod<RF,IGO,PDESOLVERSeq,U,U>;
-	using OSMPar = Dune::PDELab::OneStepMethod<RF,IGO,PDESOLVERPar,U,U>;
+	using OSM = Dune::PDELab::OneStepMethod<RF,IGO,PDESOLVER,U,U>;
 
 	// -- Utility Class Definitions -- //
 	/// VTK Output writer base class
@@ -111,12 +108,9 @@ protected:
 	std::unique_ptr<GO0> go0;
 	std::unique_ptr<GO1> go1;
 	std::unique_ptr<IGO> igo;
-	std::unique_ptr<LSSeq> ls_seq;
-	std::unique_ptr<LSPar> ls_par;
-	std::unique_ptr<PDESOLVERSeq> pdesolver_seq;
-	std::unique_ptr<PDESOLVERPar> pdesolver_par;
-	std::unique_ptr<OSMSeq> osm_seq;
-	std::unique_ptr<OSMPar> osm_par;
+	std::unique_ptr<LS> ls;
+	std::unique_ptr<PDESOLVER> pdesolver;
+	std::unique_ptr<OSM> osm;
 	TimeStepScheme alex2;
 
 	std::unique_ptr<U> uold;

testing/mass_conservation.mini.in

@@ -2,8 +2,8 @@ include ${CMAKE_BINARY_DIR}/doc/default_files/config.ini
 
 __name = mc
 _asset_path = "${CMAKE_CURRENT_LIST_DIR}"
-_limit_cube_static = 4e-7
-_limit_cube_adapt = 3E-7
+_limit_cube_static = 4E-7
+_limit_cube_adapt = 4E-7
 _limit_simplex_static = 4E-7
 _limit_simplex_adapt = 4E-7