Replacing post_processing and result with DPF

[germa89]

This is going to be tracked here: ansys/pymapdl#1298

Old issue

Summary

Currently there is duplication regarding the post-processing of MAPDL results. There are three libraries which can do this job:

• PyMAPDL Reader (legacy)
• PyMAPDL
• DPF-Post

Intended Outcome

Effort should be merged toward only one single library for post-processing. The current general agreement is to go with DPF.

Any post-processing reference and function inside pymapdl should point to DPF equivalent.

How will it work?

Retro-compatibility should be ensured.
Use DPF to implement post_processing module. It requires to change 3-4 functions which are doing most of the heavy work.

Stages/steps

• Prepare example with DPF for me to get familiar with the library. Using DPF in example pymapdl#1279
• Use DPF for the mesh module in PyMAPDL. Almost in progress...
  So far, we are pending on the VTK parser. That is key as mentioned in Mesh objects from db files pydpf-core#331
• Post-processing - It does not need to be migrated to DPF because it only uses the reader for the mesh, which should be fixed in the previous bullet point.
• Result. This is going to be tricky.

[akaszynski]

We’re going to need help from the DPF team. @rlagha, can we get help from the new hire?

[rlagha]

@akaszynski yes definitely, this is important