Can it possible to find L^2-error and order of convergence in Heat-3d PETSc code (parrallel computing)

General Discussion
8

Here PETSc example (heat-TS-2d-PETSc.edp) incorrectly imlpemented? - #11 by fb77
you can find the computation of L2 error (2d) as

//build partition of unity
fespace Vhpart(Th, P0);  // P0 elements for partition function
Vhpart part;  // Partition function
PartitionCreate(Th, part[], P0);  // Create partition using the mesh Th, part[] takes values 0 or 1

real localerr=int2d(Th)(part*(w-uexT)^2);
real globalerr;
mpiAllReduce(localerr, globalerr, mpiCommWorld, mpiSUM);
globalerr=sqrt(globalerr);
if (mpirank==0) cout << "t=" << t << " global L2 error " << globalerr << endl;

The order of convergence can be computed as in sequential codes.

1 Like