Project Meeting 2021.02.02 - ActivitySim/activitysim GitHub Wiki

Technical call

  • Discuss performance task, including location sampling improvements and PSRC testing, representative logsums mini-spec
    • Dynamic chunking was an opportunistic improvement as part of TVPB work and could be even better
      • Probably could get 25% increase in performance with additional fine tuning
      • It experiments with a few choosers and then sets chunk size
      • The chunksize setting could evolve to be more of a "allowed_machine_memory_to_use" setting, which would be better for the user
      • It could better understand overhead memory usage
      • Probably need a couple weeks to implement the improvements
    • taz/maz location sampling coming together for PSRC
      • 28 hrs into the task
      • Need to implement for non-mandatory and trip models still
      • Found a few issues in PSRC data that PSRC is fixing
      • Also implemented skipping calculations if size term == 0, which will help all models, especially sparse ones like school location
      • Implemented in 2 and 3 model setups too
      • Maybe want to implement by mode since auto uses taz data but walk uses maz data
      • Need to double check on the shadow pricing math
    • representative logsums mini-spec makes sense
      • probably need a week or some more to implement
      • will really speed up the model and will help everyone
      • current activitysim model deployments by RSG can help fund if needed
      • for scheduling models, should be 10x speed up for MTC and 100x speed up for ARC
      • some lose in parking duration precision, but typically worth it, and feature will be optional
      • it better aligns demand and network model precision
      • suggest coding these settings in the network_los.yaml for one-stop-shopping of skim/time period related settings
      • also check when settings read in so end is after start and start and end are valid for the skim time periods
    • We decided to do just these topics - taz/map location sampling and representative logsums - with the task
    • And we'll create an issue to keep track of potential performance enhancements
  • Discuss new activitysim.estimation.larch sub-package within ActivitySim
    • larch subpackage added to asim and potential for other estimation tool integration (like ALOGIT) also possible in the future
    • Tests not working since the latest numpy/pyarrow packages are inconsistent but the open source community will likely soon fix this so we'll wait
    • Jeff to keeping working on larch notebooks
    • I'll work on merging estimation, estimation_larch, and develop branches + merge Doyle's mp PR for populationsim
  • Discuss adding test coverage for ALTS_PREPROCESSOR added for ARC next time
  • Also let's review issues for any hot topics