Example building stiffness matrix for a Poisson equation using nodal (Hgrad) elements on squares. This shows how to use the local-global mapping to preallocate the matrix graph. This leads to an improvement in the time it takes to construct the global matrix. More...

#include "Intrepid_FunctionSpaceTools.hpp"
#include "Intrepid_FieldContainer.hpp"
#include "Intrepid_CellTools.hpp"
#include "Intrepid_ArrayTools.hpp"
#include "Intrepid_HGRAD_QUAD_Cn_FEM.hpp"
#include "Intrepid_RealSpaceTools.hpp"
#include "Intrepid_DefaultCubatureFactory.hpp"
#include "Intrepid_Utils.hpp"
#include "Epetra_Time.h"
#include "Epetra_Map.h"
#include "Epetra_FECrsMatrix.h"
#include "Epetra_FEVector.h"
#include "Epetra_SerialComm.h"
#include "Teuchos_oblackholestream.hpp"
#include "Teuchos_RCP.hpp"
#include "Teuchos_BLAS.hpp"
#include "Shards_CellTopology.hpp"
#include "EpetraExt_RowMatrixOut.h"
#include "EpetraExt_MultiVectorOut.h"

Functions
double	evalu (double &x, double &y, double &z)

int	evalGradu (double &x, double &y, double &z, double &gradu1, double &gradu2, double &gradu3)

double	evalDivGradu (double &x, double &y, double &z)

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

Detailed Description

Example building stiffness matrix for a Poisson equation using nodal (Hgrad) elements on squares. This shows how to use the local-global mapping to preallocate the matrix graph. This leads to an improvement in the time it takes to construct the global matrix.

         div grad u = f in Omega
                  u = 0 on Gamma 

 Discrete linear system for nodal coefficients(x):
    
             Kx = b

        K - HGrad stiffness matrix
        b - right hand side vector

Author: Created by P. Bochev, R. Kirby, D. Ridzal and K. Peterson.

Remarks

Usage

 ./Intrepid_example_Drivers_Example_05.exe N verbose

    int NX              - num intervals in x direction (assumed box domain, 0,1)
    int NY              - num intervals in x direction (assumed box domain, 0,1)
    verbose (optional)  - any character, indicates verbose output

Sample command line

./Intrepid_example_Drivers_Example_05.exe 10 10

Definition in file example_07.cpp.

Function Documentation

◆ evalDivGradu()

double evalDivGradu	(	double &	x,
		double &	y,
		double &	z
	)

Definition at line 484 of file example_07.cpp.

◆ evalGradu()

int evalGradu	(	double &	x,
		double &	y,
		double &	z,
		double &	gradu1,
		double &	gradu2,
		double &	gradu3
	)

Definition at line 463 of file example_07.cpp.

◆ evalu()

double evalu	(	double &	x,
		double &	y,
		double &	z
	)

Definition at line 449 of file example_07.cpp.

◆ main()

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