Add AMGCL support and GMRES-AMG interface

CMake/FindAMGCL.cmake

+# Copyright 2020 University of Liège
+#
+# 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.
+
+# FindAMGC.cmake - try to find AMGCL headers
+# ----------------------------------------------------------------------------
+# output:
+#    AMGCL_FOUND             : TRUE/FALSE
+#    AMGCL_INCLUDE_DIRS      : where the amgcl/*.h are              [cached]
+# ----------------------------------------------------------------------------
+# autodetection:
+#    utiliser "CMAKE_PREFIX_PATH=c:\local"
+#          ou "CMAKE_INCLUDE_PATH=c:\local\include"
+#          ou "INCLUDE=c:\local\include"
+# ----------------------------------------------------------------------------
+
+# Find the header and check the version
+find_path(AMGCL_INCLUDE_DIRS "amgcl/amg.hpp")
+if (NOT AMGCL_INCLUDE_DIRS)
+    message(FATAL_ERROR "AMGCL headers not found! Define the path in the INCLUDE environment variable.")
+endif()
+
+# handle the QUIETLY and REQUIRED arguments and set AMGCL_FOUND to TRUE
+# if all listed variables are TRUE
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(AMGCL
+                                  FOUND_VAR AMGCL_FOUND
+                                  REQUIRED_VARS AMGCL_INCLUDE_DIRS)

CMakeLists.txt

 # Copyright 2020 University of Liège
-# 
+#
 # 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.
@@ -31,7 +31,7 @@ MARK_AS_ADVANCED(LIBRARY_OUTPUT_PATH EXECUTABLE_OUTPUT_PATH)
 
 # Build type
 IF(NOT CMAKE_BUILD_TYPE)
-    SET( CMAKE_BUILD_TYPE "Release" CACHE STRING 
+    SET( CMAKE_BUILD_TYPE "Release" CACHE STRING
          "Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel."
          FORCE)
 ENDIF(NOT CMAKE_BUILD_TYPE)
@@ -63,6 +63,7 @@ ENDIF()
 OPTION(USE_VTK         "Compile with VTK"                ON)
 OPTION(USE_MKL         "Compile with Intel MKL"          ON)
 OPTION(USE_MUMPS       "Compile with MUMPS"              ON)
+OPTION(USE_AMGCL       "Compile with AMGCL"              ON)
 
 # -- DEPENDENCIES
 # Python
@@ -74,8 +75,8 @@ ELSE()
     # use Python3_ROOT_DIR if wrong python found (e.g. anaconda)
     SET(PYTHON_EXECUTABLE ${Python3_EXECUTABLE})
     SET(PYTHON_LIBRARIES ${Python3_LIBRARIES})
-    SET(PYTHON_INCLUDE_PATH ${Python3_INCLUDE_DIRS}) 
-    SET(PYTHONLIBS_VERSION_STRING ${Python3_VERSION})     
+    SET(PYTHON_INCLUDE_PATH ${Python3_INCLUDE_DIRS})
+    SET(PYTHONLIBS_VERSION_STRING ${Python3_VERSION})
 ENDIF()
 MESSAGE(STATUS "PYTHON_EXECUTABLE:FILEPATH=${PYTHON_EXECUTABLE}")
 MESSAGE(STATUS "PYTHON_LIBRARIES:FILEPATH=${PYTHON_LIBRARIES}")

tbox/_src/tboxw.h

@@ -36,6 +36,7 @@
 #include "wGaussTetra4.h"
 #include "wGaussTri3.h"
 #include "wGmres.h"
+#include "wGmresAmg.h"
 #include "wGmshExport.h"
 #include "wGmshImport.h"
 #include "wGroup.h"

tbox/_src/tboxw.i

@@ -163,6 +163,8 @@ namespace std {
 %include "wSparseLu.h"
 %shared_ptr(tbox::Gmres);
 %include "wGmres.h"
+%shared_ptr(tbox::GmresAmg);
+%include "wGmresAmg.h"
 
 %include "wUnitTest.h"
 

tbox/src/CMakeLists.txt

 # Copyright 2020 University of Liège
-# 
+#
 # 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.
@@ -57,6 +57,14 @@ FIND_PACKAGE(EIGEN 3.3.4 REQUIRED)
 TARGET_INCLUDE_DIRECTORIES(tbox PUBLIC ${EIGEN_INCLUDE_DIRS})
 TARGET_COMPILE_DEFINITIONS(tbox PUBLIC EIGEN_DONT_PARALLELIZE)
 
+# -- AMGCL --
+IF(USE_AMGCL)
+    FIND_PACKAGE(OpenMP)
+    TARGET_LINK_LIBRARIES(tbox OpenMP::OpenMP_CXX)
+    FIND_PACKAGE(AMGCL REQUIRED)
+    TARGET_INCLUDE_DIRECTORIES(tbox PUBLIC ${AMGCL_INCLUDE_DIRS})
+ENDIF()
+
 # -- MUMPS --
 IF (USE_MUMPS)
     FIND_PACKAGE(MUMPS REQUIRED)

tbox/src/wGmresAmg.cpp

+/*
+ * Copyright 2020 University of Liège
+ *
+ * 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.
+ */
+
+#include "wGmresAmg.h"
+#include <amgcl/amg.hpp>
+#include <amgcl/make_solver.hpp>
+#include <amgcl/solver/gmres.hpp>
+#include <amgcl/coarsening/smoothed_aggregation.hpp>
+#include <amgcl/relaxation/ilut.hpp>
+#include <amgcl/adapter/eigen.hpp>
+#include <amgcl/backend/eigen.hpp>
+using namespace tbox;
+
+void GmresAmg::analyze(Eigen::SparseMatrix<double> const &A)
+{
+    throw std::runtime_error("tbox::GmresAmg::analyze not implemented!\n");
+}
+void GmresAmg::factorize(Eigen::SparseMatrix<double> const &A)
+{
+    throw std::runtime_error("tbox::GmresAmg::factorize not implemented!\n");
+}
+void GmresAmg::solve(Eigen::Map<Eigen::VectorXd> const &b, Eigen::Map<Eigen::VectorXd> &x)
+{
+    throw std::runtime_error("tbox::GmresAmg::solve not implemented!\n");
+}
+void GmresAmg::compute(Eigen::SparseMatrix<double> const &A, Eigen::Map<Eigen::VectorXd> const &b, Eigen::Map<Eigen::VectorXd> &x)
+{
+    // GMRES with AMG (smoothed agreg + ILUT)
+    typedef amgcl::backend::eigen<double> Backend;
+    typedef amgcl::make_solver<amgcl::amg<Backend, amgcl::coarsening::smoothed_aggregation, amgcl::relaxation::ilut>, amgcl::solver::gmres<Backend>> Solver;
+
+    // Parameters
+    Solver::params p;
+    p.solver.M = 50;                            // restart
+    p.solver.tol = 1e-5;                        // relative tolerance
+    p.solver.maxiter = 1000;                    // max. n. iterations
+    p.precond.relax.p = 1;                      // fill-in
+    p.precond.relax.tau = 1e-6;                 // threshold
+    p.precond.ncycle = 2;                       // cycle shape (W)
+    p.precond.pre_cycles = 3;                   // number of cycles
+    p.precond.coarsening.aggr.eps_strong = 0.5; // AMG coupling
+
+    // Convert to CRS and solve
+    Eigen::SparseMatrix<double, Eigen::RowMajor> AA = A;
+    Solver sol(AA, p);
+    std::tie(it, err) = sol(AA, b, x);
+}
+
+void GmresAmg::write(std::ostream &out) const
+{
+    out << "GMRES-AMG (AMGCL)" << std::endl;
+}

tbox/src/wGmresAmg.h

+/*
+ * Copyright 2020 University of Liège
+ *
+ * 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.
+ */
+
+#ifndef WGMRESAMG_H
+#define WGMRESAMG_H
+
+#include "tbox.h"
+#include "wLinearSolver.h"
+#include <Eigen/Sparse>
+
+namespace tbox
+{
+
+/**
+ * @brief GMRES with AMG preconditioner interface
+ * @authors Adrien Crovato
+ * @todo Configure solver in constructor and public methods
+ * @todo Find optimal or good-enough parameters
+ */
+class TBOX_API GmresAmg : public LinearSolver
+{
+    int it;     ///< number of iterations
+    double err; ///< relative error
+public:
+    GmresAmg() : LinearSolver() {}
+    virtual ~GmresAmg() {}
+
+#ifndef SWIG
+    virtual void analyze(Eigen::SparseMatrix<double> const &A) override;
+    virtual void factorize(Eigen::SparseMatrix<double> const &A) override;
+    virtual void solve(Eigen::Map<Eigen::VectorXd> const &b, Eigen::Map<Eigen::VectorXd> &x) override;
+    virtual void compute(Eigen::SparseMatrix<double> const &A, Eigen::Map<Eigen::VectorXd> const &b, Eigen::Map<Eigen::VectorXd> &x) override;
+
+    virtual double getError() override { return err; }
+    virtual int getIterations() override { return it; }
+
+    virtual void write(std::ostream &out) const override;
+#endif
+};
+
+} // namespace tbox
+
+#endif // WGMRESAMG_H