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Postprocessing Reference

Postprocessing reads solution data and writes derived outputs such as VTK files, QoI files, visualization fields, and CG output fields.

Configuration Fields

Field/key Scope Default Meaning
saveParaview Runtime 0 Enable VTK/ParaView output when visualization fields are defined.
nsca Runtime 0 Number of scalar visualization fields.
nvec Runtime 0 Number of vector visualization fields.
nten Runtime 0 Number of tensor visualization fields.
nsurf Runtime 0 Number of surface output components.
nvqoi Runtime 0 Number of volume QoI components.
saveSolFreq Runtime 1 Saved solution frequency.
saveSolOpt Runtime 1 Saved solution storage option.
executionmode Frontend-only 0 1 launches standalone postprocess mode from frontends.

Model Functions Used by Postprocessing

Function Output
VisScalars Scalar fields for VTK output.
VisVectors Vector fields for VTK output.
VisTensors Tensor fields for VTK output.
QoIvolume Volume QoI integrands.
QoIboundary Boundary QoI integrands.
Output DG output field.

Solve-Time Output

Solve mode writes saved solution files and optionally postprocessing outputs depending on the runtime flags. saveParaview = 1 is required for VTK output.

Standalone Postprocess Mode

Generated apps and app-mode executables can run in postprocess mode. In this mode the executable reads saved solution records and writes derived output without rerunning the nonlinear solver.

Frontend executionmode = 1 is a helper that makes runcode launch the generated executable with postprocess semantics.

Saved Solution Replay

Postprocessing can read:

  • Final solution files through ReadSolutions.
  • Specific saved records through GetSolutions(record_index).

For compact saved solution formats, Exasim reconstructs missing quantities such as q when required for visualization or QoI.

Output Files

Common outputs include:

Output Meaning
outudg_np*.bin Rank-local solution data.
outwdg_np*.bin Rank-local auxiliary w data, when present.
outuhat_np*.bin HDG trace data, when present.
out_residualnorms*.bin Residual history when enabled.
outqoi.txt Quantities of interest.
*.vtu, *.pvtu, *.pvd ParaView visualization files.

MPI Behavior

MPI runs write rank-local binary outputs and parallel VTK metadata where enabled. QoI and visualization routines must avoid double-counting ghost elements.