Merge pull request #12350 from KratosMultiphysics/core/define-list-fa…

…stest-direct-linear-solvers

[Core][TrilinosApplication] Defning list of fastest direct linear solvers.

applications/TrilinosApplication/custom_python/add_trilinos_space_to_python.cpp

@@ -313,6 +313,8 @@ void  AddBasicOperations(pybind11::module& m)
     .def("SetValue", SetValue)
     //.def("GetValue", GetValue) //deliberately commented out. Only works for local Ids
     .def("GatherValues", GatherValues)
+    .def_static("IsDistributed", &TrilinosSparseSpaceType::IsDistributed)
+    .def_static("FastestDirectSolverList", &TrilinosSparseSpaceType::FastestDirectSolverList)
     ;
 
     m.def("CreateCommunicator", CreateCommunicator);

applications/TrilinosApplication/trilinos_space.h

@@ -862,6 +862,28 @@ class TrilinosSpace
         return true;
     }
 
+    /**
+     * @brief Returns a list of the fastest direct solvers.
+     * @details This function returns a vector of strings representing the names of the fastest direct solvers. The order of the solvers in the list may need to be updated and reordered depending on the size of the equation system.
+     * @return A vector of strings containing the names of the fastest direct solvers.
+     */
+    inline static std::vector<std::string> FastestDirectSolverList()
+    {
+        // May need to be updated and reordered. In fact I think it depends of the size of the equation system
+        std::vector<std::string> faster_direct_solvers({
+            "mumps2",         // Amesos2 (if compiled with MUMPS-support)
+            "mumps",          // Amesos (if compiled with MUMPS-support)
+            "super_lu_dist2", // Amesos2 SuperLUDist (if compiled with MPI-support)
+            "super_lu_dist",  // Amesos SuperLUDist (if compiled with MPI-support)
+            "amesos2",        // Amesos2
+            "amesos",         // Amesos
+            "klu2",           // Amesos2 KLU
+            "klu",            // Amesos KLU
+            "basker"          // Amesos2 Basker
+        });
+        return faster_direct_solvers;
+    }
+
     /**
      * @brief This function returns a value from a given vector according to a given index
      * @param rX The vector from which values are to be gathered

kratos/python/add_sparse_matrices_to_python.cpp

@@ -1,4 +1,3 @@
-
 //    |  /           |
 //    ' /   __| _` | __|  _ \   __|
 //    . \  |   (   | |   (   |\__ `

kratos/python/add_strategies_to_python.cpp

@@ -521,9 +521,16 @@ namespace Kratos:: Python
 
         auto sparse_space_binder = CreateSpaceInterface< SparseSpaceType >(m,"UblasSparseSpace");
         sparse_space_binder.def("TwoNorm", TwoNorm);
-        //the dot product of two vectors
+        // The dot product of two vectors
         sparse_space_binder.def("Dot", Dot);
         sparse_space_binder.def("TransposeMult", TransposeMult);
+        // Size functions
+        sparse_space_binder.def("Size", &SparseSpaceType::Size);
+        sparse_space_binder.def("Size1", &SparseSpaceType::Size1);
+        sparse_space_binder.def("Size2", &SparseSpaceType::Size2);
+        // Information functions
+        sparse_space_binder.def("IsDistributed", &SparseSpaceType::IsDistributed);
+        sparse_space_binder.def("FastestDirectSolverList", &SparseSpaceType::FastestDirectSolverList);
 
         auto cplx_sparse_space_binder = CreateSpaceInterface< ComplexSparseSpaceType >(m,"UblasComplexSparseSpace");
 

kratos/python_scripts/python_linear_solver_factory.py

@@ -2,7 +2,6 @@
 from KratosMultiphysics import kratos_utilities as kratos_utils
 from importlib import import_module
 
-
 def ConstructSolver(configuration):
     if(type(configuration) != KM.Parameters):
         raise Exception("input is expected to be provided as a Kratos Parameters object")
@@ -26,11 +25,7 @@ def CreateFastestAvailableDirectLinearSolver():
     if kratos_utils.CheckIfApplicationsAvailable("LinearSolversApplication"):
         from KratosMultiphysics import LinearSolversApplication
 
-    linear_solvers_by_speed = [
-        "pardiso_lu", # LinearSolversApplication (if compiled with Intel-support)
-        "sparse_lu",  # LinearSolversApplication
-        "skyline_lu_factorization" # in Core, always available, but slow
-    ]
+    linear_solvers_by_speed = KM.UblasSparseSpace.FastestDirectSolverList()
 
     for solver_name in linear_solvers_by_speed:
         if KM.LinearSolverFactory().Has(solver_name):
@@ -41,7 +36,6 @@ def CreateFastestAvailableDirectLinearSolver():
 
     raise Exception("Linear-Solver could not be constructed!")
 
-
 def __GetSolverTypeAndImportApplication(solver_type):
     # remove unused "KratosMultiphysics.
     if solver_type.startswith("KratosMultiphysics."):
@@ -57,5 +51,4 @@ def __GetSolverTypeAndImportApplication(solver_type):
         solver_type = splitted_name[1]
         import_module("KratosMultiphysics." + app_name)
 
-    return solver_type
-
+    return solver_type

kratos/spaces/ublas_space.h

@@ -891,6 +891,22 @@ class UblasSpace
         return false;
     }
 
+    /**
+     * @brief Returns a list of the fastest direct solvers.
+     * @details This function returns a vector of strings representing the names of the fastest direct solvers. The order of the solvers in the list may need to be updated and reordered depending on the size of the equation system.
+     * @return A vector of strings containing the names of the fastest direct solvers.
+     */
+    inline static std::vector<std::string> FastestDirectSolverList()
+    {
+        std::vector<std::string> faster_direct_solvers({
+            "pardiso_lu",              // LinearSolversApplication (if compiled with Intel-support)
+            "pardiso_ldlt",            // LinearSolversApplication (if compiled with Intel-support)
+            "sparse_lu",               // LinearSolversApplication
+            "skyline_lu_factorization" // In Core, always available, but slow
+        });
+        return faster_direct_solvers;
+    }
+
     //***********************************************************************
 
     inline static TDataType GetValue(const VectorType& x, std::size_t I)