Afivo can write output in the Silo and the VTK unstructured format. The Silo format has some advantages:

Large files can be viewed more efficiently (important in 3D)
Ghost cells are included in the output, so that contours and surface plots don't 'break' near refinement boundaries

At the moment, only cell-centered variables are included in the output.

Writing Silo/VTK files

The routines for writing Silo and VTK files are m_a2_output::a2_write_silo and m_a2_output::a2_write_vtk, with equivalents in 3D. These routines can be called as follows:

! To write "output/test.silo"
call a2_write_silo(tree, "test", dir="output")

! To write "output/test.vtu"
call a2_write_vtk(tree, "test", dir="output")

They write the full mesh structure, and by default include all cell-centered variables. Because files can get pretty big in 3D, there is an optional argument ixs_cc. By specifying e.g. ixs_cc = [1,2] only the first two variables will be included in the output. There are also optional arguments n_cycle and time, which correspond to the simulation cycle (number) and the simulation time.

Writing a plane

Sometimes it is convenient to write the solution in some region with a uniform resolution. For this purpose there is the routine m_a2_output::a2_write_plane, which writes a VTK file.

Visualizing results

The Silo and VTK files can be visualized with Visit. Consult the Visit manual or one of the tutorials for more details.