Binning Plugin TODOs and Roadmap

[ikbuibui]

TODOs for the flexible Binning plugin

• [ ] Support binning of vector quantities
• [ ] Support for binning only inside the moving window
• [ ] Bin a particle multiple times - Useful for RNG based functors, say to generate distributions
• [ ] Add ability to apply post processing functor on the histogram before doing a data dump
• [ ] Discuss sane defaults, default examples and pre-define functors for common quantities (Maybe as a PICMI extension?)
• [ ] Split the binning histogram across GPUs according to domain decomposition if position axes are defined.
  • Rather than holding the full binning on each GPU
  • This decomposition will enforce that bins should not cross GPU boundaries, and be multiples of supercells or a natural number of bins per supercell
• [ ] Reduce (MPI) the binning histogram buffer in place
• [ ] Auto binning ranges and splitting - Automatically and dynamically in the simulation choose binning range min, max and number of bins
• [x] Profile the binning
  • [ ] Global memory atomics are super slow. Transition to using shared memory where possible.
• [ ] Add more axes
  • [x] Log Axes
  • [ ] Generic Axes defined with edges
  • [ ] LogLinLog Axes (symlog)
  • [ ] String Axes
• [x] Option to only bin particles which are leaving (#5039) (https://github.com/ComputationalRadiationPhysics/picongpu/issues/4946#issuecomment-2180457170)
• [x] Restart and Checkpoint Support (#4766)
• [x] Add ability to disable overflow bins (#4770)
• [x] Particle Filtering - Bin/Don't bin particles matching certain criteria (#5249)
• [x] Bin fields (also particles with fields) (#5319) (requested #4972)
• [x] Add flexible accumulation methods (#5289)

[psychocoderHPC]

@ikbuibui If I do not miss something then the binning plugin is missing the OpenMPD annotation if a value is including the weighting and how it scales with the weighting. The only OpenPMD anotation the user can pass the openPMD unit description.

[ikbuibui]

As discussed in the office, the weighting is a particle property and not a property of bins, so the the weighting annotation for bins makes no sense. If the user needs special treatment of weighted quantities it can be done inside the functors.