Dear Muhammad, I think Ross implemented vector_value_list() this way so that he could use one function object to give correct values with multiple material IDs: see
https://github.com/rosskynch/MIT_Forward/blob/master/src/forwardsolver.cc#L724 to see where he uses an object inheriting from EddyCurrentFunction to do exactly this (though in that case he uses this function to set up the right-hand side instead of boundary values). Several are implemented here: https://github.com/rosskynch/MIT_Forward/blob/master/include/backgroundfield.h#L46 Thanks, David On Thu, Sep 12, 2019 at 4:54 AM Muhammad Adil <[email protected]> wrote: > Hello, > I am trying to understand the MIT code written by Ross Kynch. > I am facing a problem to understand the implementation of boundary > conditions. > As we know we impose boundary conditions to calcluate the unknown > coefficients. I don't understand how is he implementing the code given > below to determine the coefficients? > > I don't know why he defined two functions: > virtual void vector_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values) const; > virtual void vector_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const; > > ////////////////////Header File///////////////////////////////////// > > > template<int dim> > class curlFunction : public Function<dim> > { > public: > // curlFunction ();//unsigned int n_components = dim+dim); > virtual void curl_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values) const = 0; > //virtual void perturbed_field_value_list (const std::vector<Point<dim> > > &points, > // std::vector<Vector<double> > &values) const = 0; > }; > > template<int dim> > class perturbedFunction : public curlFunction<dim> > { > public: > // perturbedFunction ();//unsigned int n_components = dim+dim); > virtual void curl_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values) const = 0; > virtual void perturbed_field_value_list (const std::vector<Point<dim> > & > points, > std::vector<Vector<double> > &values) const = 0; > }; > > // Base Function class for all EddyCurrent problems. > // The idea here is to allow implementation of boundary conditions of the > type: > // n x E = f (Dirichlet) and n x curl(E) = g (Neumann) > // > // which can be handled through the vector_value_list and curl_value_list > functions. > // > // The RHS of the equation can be handled through the rhs_value_list. > // > // The perturbed_field_value_list can be used for comparison with > analytical/asymptotic formulae. > // > // We also include the boolean function zero_xxx() for each to return if > the function is simply zero. > // this allows us to avoid wasted computation which are automatically zero > (e.g. in RHS assembly). > // > // We also include the option of passing a material_id to the function. > Since we are typically > // dealing with subdomains where we have conducting/non-conducting > objects, this allows communication > // from structure in the mesh to the function, if required (default is > off). > template<int dim> > class EddyCurrentFunction : public Function<dim> > { > public: > // Leave out constructor for now, we may need to create one which > // calls the Function constructor with n_components = dim+dim by default). > //EddyCurrentFunction (unsigned int n_components = dim+dim); > // We overload each member so that it implements the style found in > Function<dim> > // as well as allowing the use of the material_id if required. > // The obvious way to do this is to implement the Function<dim>-style > version by > // calling the material_id version with numbers::invalid_material_id, > // effectively making it the default value for that argument. > // > // Obviously derived classes an bypass this if required. > virtual void vector_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values) const; > virtual void vector_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const; > virtual void curl_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values) const; > > virtual void curl_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const; > virtual void perturbed_field_value_list (const std::vector<Point<dim> > & > points, > std::vector<Vector<double> > &values) const; > > virtual void perturbed_field_value_list (const std::vector<Point<dim> > & > points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const; > > virtual void rhs_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values) const; > virtual void rhs_value_list (const std::vector<Point<dim> > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const; > virtual void scattered_field_value_list (const std::vector<Point<dim> > & > points, > std::vector<Vector<double> > &values) const; > virtual void scattered_field_value_list (const std::vector<Point<dim> > & > points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const; > > virtual bool zero_vector() const { return true; } > virtual bool zero_curl() const { return true; } > virtual bool zero_perturbed() const { return true; } > virtual bool zero_rhs() const { return true; } > virtual bool zero_scattered() const { return true; } > }; > > /////////////////////.CC > File//////////////////////////////////////////////// > > > > // Implementation of the virtual functions for EddyCurrentFunction: > // In all cases we just return zero, and so set the zero_xxx boolean > function to return true. > // This means that any derived classes will need to implement pairs of the > appropriate xxx_value_list > // and zero_xxx (returning false) functions. > template<int dim> > void EddyCurrentFunction<dim>::vector_value_list (const std::vector<Point< > dim> > &points, > std::vector<Vector<double> > &values) const > { > vector_value_list(points, values, numbers::invalid_material_id); > } > > template<int dim> > void EddyCurrentFunction<dim>::vector_value_list (const std::vector<Point< > dim> > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const > { > Assert(values.size() == points.size(), ExcDimensionMismatch(values.size(), > points.size())); > for (unsigned int k=0; k<points.size(); ++k) > { > values[k]=0; > } > } > > template<int dim> > void EddyCurrentFunction<dim>::curl_value_list (const std::vector<Point< > dim> > &points, > std::vector<Vector<double> > &values) const > { > curl_value_list(points, values, numbers::invalid_material_id); > } > > template<int dim> > void EddyCurrentFunction<dim>::curl_value_list (const std::vector<Point< > dim> > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const > { > Assert(values.size() == points.size(), ExcDimensionMismatch(values.size(), > points.size())); > for (unsigned int k=0; k<points.size(); ++k) > { > values[k]=0; > } > } > > template<int dim> > void EddyCurrentFunction<dim>::perturbed_field_value_list (const std > ::vector<Point<dim> > &points, > std::vector<Vector<double> > &values) const > { > perturbed_field_value_list(points, values, numbers::invalid_material_id); > } > > template<int dim> > void EddyCurrentFunction<dim>::perturbed_field_value_list (const std > ::vector<Point<dim> > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const > { > Assert(values.size() == points.size(), ExcDimensionMismatch(values.size(), > points.size())); > for (unsigned int k=0; k<points.size(); ++k) > { > values[k]=0; > } > } > > template<int dim> > void EddyCurrentFunction<dim>::rhs_value_list (const std::vector<Point<dim > > > &points, > std::vector<Vector<double> > &values) const > { > rhs_value_list(points, values, numbers::invalid_material_id); > } > > template<int dim> > void EddyCurrentFunction<dim>::rhs_value_list (const std::vector<Point<dim > > > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const > { > Assert(values.size() == points.size(), ExcDimensionMismatch(values.size(), > points.size())); > for (unsigned int k=0; k<points.size(); ++k) > { > values[k]=0; > } > } > > template<int dim> > void EddyCurrentFunction<dim>::scattered_field_value_list (const std > ::vector<Point<dim> > &points, > std::vector<Vector<double> > &values) const > { > scattered_field_value_list(points, values, numbers::invalid_material_id); > } > > template<int dim> > void EddyCurrentFunction<dim>::scattered_field_value_list (const std > ::vector<Point<dim> > &points, > std::vector<Vector<double> > &values, > const types::material_id &mat_id) const > { > Assert(values.size() == points.size(), ExcDimensionMismatch(values.size(), > points.size())); > for (unsigned int k=0; k<points.size(); ++k) > { > values[k]=0; > } > } > > template class EddyCurrentFunction<3>; > > -- > The deal.II project is located at http://www.dealii.org/ > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > --- > You received this message because you are subscribed to the Google Groups > "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/dealii/71ee42b0-9a26-4e20-aa18-2d32c7fad207%40googlegroups.com > <https://groups.google.com/d/msgid/dealii/71ee42b0-9a26-4e20-aa18-2d32c7fad207%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. 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