Add a parameter object on the system, use it in derived classes

examples/miscellaneous/miscellaneous_ex7/biharmonic_jr.C

@@ -99,18 +99,18 @@ void Biharmonic::JR::initialize()
   if (_biharmonic._verbose)
     libMesh::out << ">>> Initializing Biharmonic::JR\n";
 
-  Parameters parameters;
-  parameters.set<Point>("center") = _biharmonic._initialCenter;
-  parameters.set<Real>("width")   = _biharmonic._initialWidth;
+  Parameters params;
+  params.set<Point>("center") = _biharmonic._initialCenter;
+  params.set<Real>("width")   = _biharmonic._initialWidth;
 
   if (_biharmonic._initialState == Biharmonic::BALL)
-    project_solution(Biharmonic::JR::InitialDensityBall, Biharmonic::JR::InitialGradientZero, parameters);
+    project_solution(Biharmonic::JR::InitialDensityBall, Biharmonic::JR::InitialGradientZero, params);
 
   if (_biharmonic._initialState == Biharmonic::ROD)
-    project_solution(Biharmonic::JR::InitialDensityRod, Biharmonic::JR::InitialGradientZero, parameters);
+    project_solution(Biharmonic::JR::InitialDensityRod, Biharmonic::JR::InitialGradientZero, params);
 
   if (_biharmonic._initialState == Biharmonic::STRIP)
-    project_solution(Biharmonic::JR::InitialDensityStrip, Biharmonic::JR::InitialGradientZero, parameters);
+    project_solution(Biharmonic::JR::InitialDensityStrip, Biharmonic::JR::InitialGradientZero, params);
 
   // both states are equal
   *(old_local_solution) = *(current_local_solution);
@@ -125,13 +125,13 @@ void Biharmonic::JR::initialize()
 
 
 Number Biharmonic::JR::InitialDensityBall(const Point & p,
-                                          const Parameters & parameters,
+                                          const Parameters & params,
                                           const std::string &,
                                           const std::string &)
 {
   // Initialize with a ball in the middle, which is a segment in 1D, a disk in 2D and a ball in 3D.
-  Point center = parameters.get<Point>("center");
-  Real width = parameters.get<Real>("width");
+  Point center = params.get<Point>("center");
+  Real width = params.get<Real>("width");
   Point pc = p-center;
   Real r = pc.norm();
   return (r < width) ? 1.0 : -0.5;
@@ -141,13 +141,13 @@ Number Biharmonic::JR::InitialDensityBall(const Point & p,
 
 
 Number Biharmonic::JR::InitialDensityRod(const Point & p,
-                                         const Parameters & parameters,
+                                         const Parameters & params,
                                          const std::string &,
                                          const std::string &)
 {
   // Initialize with a rod in the middle so that we have a z-homogeneous system to model the 2D disk.
-  Point center = parameters.get<Point>("center");
-  Real width = parameters.get<Real>("width");
+  Point center = params.get<Point>("center");
+  Real width = params.get<Real>("width");
   Point pc = p-center;
 #if LIBMESH_DIM > 2
   pc(2) = 0;
@@ -161,13 +161,13 @@ Number Biharmonic::JR::InitialDensityRod(const Point & p,
 
 
 Number Biharmonic::JR::InitialDensityStrip(const Point & p,
-                                           const Parameters & parameters,
+                                           const Parameters & params,
                                            const std::string &,
                                            const std::string &)
 {
   // Initialize with a wide strip in the middle so that we have a yz-homogeneous system to model the 1D.
-  Point center = parameters.get<Point>("center");
-  Real width = parameters.get<Real>("width");
+  Point center = params.get<Point>("center");
+  Real width = params.get<Real>("width");
   Real r = sqrt((p(0)-center(0))*(p(0)-center(0)));
   return (r < width) ? 1.0 : -0.5;
 }

examples/miscellaneous/miscellaneous_ex7/biharmonic_jr.h

@@ -46,17 +46,17 @@ class Biharmonic::JR : public TransientNonlinearImplicitSystem,
    * Static functions to be used for initialization
    */
   static Number InitialDensityBall(const Point & p,
-                                   const Parameters & parameters,
+                                   const Parameters & params,
                                    const std::string &,
                                    const std::string &);
 
   static Number InitialDensityRod(const Point & p,
-                                  const Parameters & parameters,
+                                  const Parameters & params,
                                   const std::string &,
                                   const std::string &);
 
   static Number InitialDensityStrip(const Point & p,
-                                    const Parameters & parameters,
+                                    const Parameters & params,
                                     const std::string &,
                                     const std::string &);
 

include/systems/system.h

@@ -27,6 +27,7 @@
 #include "libmesh/fem_function_base.h"
 #include "libmesh/libmesh_common.h"
 #include "libmesh/parallel_object.h"
+#include "libmesh/parameters.h"
 #include "libmesh/qoi_set.h"
 #include "libmesh/reference_counted_object.h"
 #include "libmesh/tensor_value.h" // For point_hessian
@@ -60,7 +61,6 @@ class MeshBase;
 class Xdr;
 class DofMap;
 template <typename Output> class FunctionBase;
-class Parameters;
 class ParameterVector;
 class Point;
 class SensitivityData;
@@ -510,8 +510,6 @@ class System : public ReferenceCountedObject<System>,
    * user-provided cloneable functors.
    * A gradient \p g is only required/used for projecting onto finite
    * element spaces with continuous derivatives.
-   * If non-default \p Parameters are to be used, they can be provided
-   * in the \p parameters argument.
    */
   void project_solution (FunctionBase<Number> * f,
                          FunctionBase<Gradient> * g = nullptr) const;
@@ -522,8 +520,6 @@ class System : public ReferenceCountedObject<System>,
    * user-provided cloneable functors.
    * A gradient \p g is only required/used for projecting onto finite
    * element spaces with continuous derivatives.
-   * If non-default \p Parameters are to be used, they can be provided
-   * in the \p parameters argument.
    */
   void project_solution (FEMFunctionBase<Number> * f,
                          FEMFunctionBase<Gradient> * g = nullptr) const;
@@ -554,8 +550,6 @@ class System : public ReferenceCountedObject<System>,
    * user-provided cloneable functors.
    * A gradient \p g is only required/used for projecting onto finite
    * element spaces with continuous derivatives.
-   * If non-default \p Parameters are to be used, they can be provided
-   * in the \p parameters argument.
    *
    * Constrain the new vector using the requested adjoint rather than
    * primal constraints if is_adjoint is non-negative.
@@ -572,8 +566,6 @@ class System : public ReferenceCountedObject<System>,
    * user-provided cloneable functors.
    * A gradient \p g is only required/used for projecting onto finite
    * element spaces with continuous derivatives.
-   * If non-default \p Parameters are to be used, they can be provided
-   * in the \p parameters argument.
    *
    * Constrain the new vector using the requested adjoint rather than
    * primal constraints if is_adjoint is non-negative.
@@ -611,8 +603,6 @@ class System : public ReferenceCountedObject<System>,
    * user-provided cloneable functors.
    * A gradient \p g is only required/used for projecting onto finite
    * element spaces with continuous derivatives.
-   * If non-default \p Parameters are to be used, they can be provided
-   * in the \p parameters argument.
    */
   void boundary_project_solution (const std::set<boundary_id_type> & b,
                                   const std::vector<unsigned int> & variables,
@@ -648,8 +638,6 @@ class System : public ReferenceCountedObject<System>,
    * user-provided cloneable functors.
    * A gradient \p g is only required/used for projecting onto finite
    * element spaces with continuous derivatives.
-   * If non-default \p Parameters are to be used, they can be provided
-   * in the \p parameters argument.
    *
    * Constrain the new vector using the requested adjoint rather than
    * primal constraints if is_adjoint is non-negative.
@@ -1531,6 +1519,9 @@ class System : public ReferenceCountedObject<System>,
    */
   virtual void prolong_vectors ();
 
+  /// Parameters for the system. If a parameter is not provided, it should be retrieved from the EquationSystems
+  Parameters parameters;
+
   /**
    * Flag which tells the system to whether or not to
    * call the user assembly function during each call to solve().

src/systems/eigen_system.C

@@ -222,16 +222,20 @@ EigenSystem::solve_helper(SparseMatrix<Number> * const A,
   // Get the tolerance for the solver and the maximum
   // number of iterations. Here, we simply adopt the linear solver
   // specific parameters.
-  const double tol          =
+  const double tol          =  parameters.have_parameter<Real>("linear solver tolerance") ?
+    double(parameters.get<Real>("linear solver tolerance")) :
     double(es.parameters.get<Real>("linear solver tolerance"));
 
-  const unsigned int maxits =
+  const unsigned int maxits = parameters.have_parameter<unsigned int>("linear solver maximum iterations") ?
+    parameters.get<unsigned int>("linear solver maximum iterations") :
     es.parameters.get<unsigned int>("linear solver maximum iterations");
 
-  const unsigned int nev    =
+  const unsigned int nev    = parameters.have_parameter<unsigned int>("eigenpairs") ?
+    parameters.get<unsigned int>("eigenpairs") :
     es.parameters.get<unsigned int>("eigenpairs");
 
-  const unsigned int ncv    =
+  const unsigned int ncv    = parameters.have_parameter<unsigned int>("basis vectors") ?
+    parameters.get<unsigned int>("basis vectors") :
     es.parameters.get<unsigned int>("basis vectors");
 
   std::pair<unsigned int, unsigned int> solve_data;

src/systems/frequency_system.C

@@ -112,6 +112,10 @@ void FrequencySystem::init_data ()
   // make sure we have frequencies to solve for
   if (!_finished_set_frequencies)
     {
+      // not supported for now
+      if (parameters.have_parameter<unsigned int> ("n_frequencies"))
+        libmesh_not_implemented_msg("ERROR: Setting the n_frequencies parameter on the system is not supported");
+
       // when this system was read from file, check
       // if this has a "n_frequencies" parameter,
       // and initialize us with these.
@@ -339,10 +343,7 @@ void FrequencySystem::solve (const unsigned int n_start,
   // Get the user-specified linear solver tolerance,
   //     the user-specified maximum # of linear solver iterations,
   //     the user-specified wave speed
-  const Real tol            =
-    es.parameters.get<Real>("linear solver tolerance");
-  const unsigned int maxits =
-    es.parameters.get<unsigned int>("linear solver maximum iterations");
+  const auto [maxits, tol] = this->get_linear_solve_parameters();
 
   // start solver loop
   for (unsigned int n=n_start; n<= n_stop; n++)