mesh_from_xfig_poisson.cc File Reference

#include "generic.h"
#include "poisson.h"
#include "meshes/triangle_mesh.h"

Classes
class	PoissonProblem< ELEMENT >
	Micky mouse Poisson problem. More...

Namespaces
	TanhSolnForPoisson
	Namespace for exact solution for Poisson equation with "sharp step".

Functions
void	TanhSolnForPoisson::get_exact_u (const Vector< double > &x, Vector< double > &u)
	Exact solution as a Vector. More...
void	TanhSolnForPoisson::get_exact_u (const Vector< double > &x, double &u)
	Exact solution as a scalar. More...
void	TanhSolnForPoisson::get_source (const Vector< double > &x, double &source)
	Source function to make it an exact solution. More...
int	main (int argc, char *argv[])
	Demonstrate how to solve Poisson problem. More...

Variables
double	TanhSolnForPoisson::X_shift =8.0
	Shift of step along x-direction. More...
bool	TanhSolnForPoisson::TanhSoln =false
	Flag for zero TanhSolution. More...

Function Documentation

main()

int main	(	int argc	,
		char *	argv[]
	)

Demonstrate how to solve Poisson problem.

{
 // Store command line arguments
 CommandLineArgs::setup(argc,argv);
 
 // Check number of command line arguments: Need exactly four.
 if (argc!=4)
  {
   std::string error_message =
    "Wrong number of command line arguments.\n";
   error_message +=
    "Must specify the following file names  \n";
   error_message += 
    "filename.node then filename.ele then filename.poly\n";
 
   throw OomphLibError(error_message,
                       OOMPH_CURRENT_FUNCTION,
                       OOMPH_EXCEPTION_LOCATION);
  }
 
 
 
 // Convert arguments to strings that specify the input file names
 string node_file_name(argv[1]);
 string element_file_name(argv[2]);
 string poly_file_name(argv[3]);
 
 // Label for output
 DocInfo doc_info;
 
 // Output directory
 doc_info.set_directory("RESLT");
 
 
 
 // Linear Elements
 //----------------
 {
  cout << std::endl << "Linear elements" << std::endl;
  cout <<              "===============" << std::endl << std::endl;
  
  //Set up the problem
  PoissonProblem<TPoissonElement<2,2> > 
   problem(&TanhSolnForPoisson::get_source,
           node_file_name,
           element_file_name,
           poly_file_name);
 
  // Use TanhSolution?
  TanhSolnForPoisson::TanhSoln=true;
  
  // Solve once with forcing that makes TanhSolution an exact solution
  // and once with constant source fct and zero bc
  unsigned nstep=2;
  for (unsigned istep=0;istep<nstep;istep++)
   {
    // Solve the problem
    problem.newton_solve();
    
    //Output solution
    problem.doc_solution(doc_info);
    
    //Increment counter for solutions 
    doc_info.number()++;
    
    // Use TanhSolution?
    TanhSolnForPoisson::TanhSoln=false;   
   }
 }
 
 
 // Quadratic Elements
 //-------------------
 {
  cout << std::endl  << "Quadratic elements" << std::endl;
  cout <<               "===================" << std::endl << std::endl;
 
  //Set up the problem
  PoissonProblem<TPoissonElement<2,3> > 
   problem(&TanhSolnForPoisson::get_source,
           node_file_name,
           element_file_name,
           poly_file_name);
 
  // Use TanhSolution?
  TanhSolnForPoisson::TanhSoln=true;
  
  // Solve once with forcing that makes TanhSolution an exact solution
  // and once with constant source fct and zero bc
  unsigned nstep=2;
  for (unsigned istep=0;istep<nstep;istep++)
   {
    // Solve the problem
    problem.newton_solve();
    
    //Output solution
    problem.doc_solution(doc_info);
    
    //Increment counter for solutions 
    doc_info.number()++;
    
    // Use TanhSolution?
    TanhSolnForPoisson::TanhSoln=false;   
   }
 }
 
 
 // Cubic Elements
 //---------------
 {
  cout << std::endl << "Cubic elements" << std::endl;
  cout <<              "==============" << std::endl << std::endl;
 
  //Set up the problem
  PoissonProblem<TPoissonElement<2,4> > 
   problem(&TanhSolnForPoisson::get_source,
           node_file_name,
           element_file_name,
           poly_file_name);
 
  // Use TanhSolution?
  TanhSolnForPoisson::TanhSoln=true;
  
  // Solve once with forcing that makes TanhSolution an exact solution
  // and once with constant source fct and zero bc
  unsigned nstep=2;
  for (unsigned istep=0;istep<nstep;istep++)
   {
    // Solve the problem
    problem.newton_solve();
    
    //Output solution
    problem.doc_solution(doc_info);
    
    //Increment counter for solutions 
    doc_info.number()++;
    
    // Use TanhSolution?
    TanhSolnForPoisson::TanhSoln=false;   
   }
 }
 
 
 
 
}

References TanhSolnForPoisson::get_source(), oomph::DocInfo::number(), OOMPH_CURRENT_FUNCTION, OOMPH_EXCEPTION_LOCATION, problem, oomph::DocInfo::set_directory(), Flag_definition::setup(), oomph::Global_string_for_annotation::string(), and TanhSolnForPoisson::TanhSoln.