Finite difference example

[streeve]

Add new example. Use a new directory to differentiate between the tutorial for individual components

TODO: add a link in the wiki somewhere (proxy app page?)

[streeve]

@colemanjs FYI

[kwitaechong]

It might be a good idea to add comment about the problem. I think this is about unsteady heat equation problem in 3d.

The governing equstion : $$\rho c_p dT/dt = k \nabla^2{T} + q$$
Neumann boundary condition (describing heat flux ) : $$k \nabla{T} \cdot n = f$$

[colemanjs]

@kwitaechong, you are correct. This boundary conditions is just an adiabatic one. I will correct the description.

Also, it is worth pointing out that I think the left-hand and right-hand sides are swapped...

[streeve]

@colemanjs can you add a more detailed comment below?

[dalg24]

Suggested change

	#include <math.h>
	#include <cmath>

[streeve]

Fixed

[dalg24]

Suggested change

	MPI_Init( &argc, &argv );
	{
	Kokkos::ScopeGuard scope_guard( argc, argv );
	finiteDifference();
	}
	MPI_Finalize();
	MPI_Init( &argc, &argv );
	Kokkos::initialize( argc, argv );
	finiteDifference();
	Kokkos::finalize();
	MPI_Finalize();

is more readable IMO

[streeve]

Updated