Project Meeting 2021.03.30 - ActivitySim/activitysim GitHub Wiki

Technical Meeting

Issues review
- I'll comment on #396 and Newman fixed #398 in the upcoming PR
Update on SANDAG performance testing
- Runtimes for example_sandag are now 5 hours on our server
- We did the following to get the runtimes down:
  - Add de-dup/re-dup of TVPB alts in accessibility calculator to reduce redundancy of calculations
  - Improve table join performance in TVPB
  - Smarter handling of TVPB market segment management related to time-of-day
  - Include use of tap lines in configuration to trim the potential TAP to TAP choice set
  - Created an example_sandag setup under activitysim\develop for testing/debugging, including a change log of revisions
  - Improved trip destination expressions to save runtime
  - Somewhat tuned chunking settings for running on our machine
- And here’s some ideas for future possible speed-ups:
  - Move from strings to factors
    - Quick/hack testing by revising input data / expressions only
    - And/or comprehensive automatic support of factors through software improvements
  - Exponentiate ahead of time TAP to TAP utilities, along with pre-computing access/egress costs
  - Smarter binary search / picking of an alternative from a large choice set (such as for location choice)
  - Make trip destination (i.e. intermediate stop location choice) aware of the tour mode so:
    - For bike, walk, transit to reduce the set of possible mazs ahead of time
    - For auto, to pre-compute TAZ to TAZ total utilities to avoid duplication of calculations
  - Smarter chunking calculations to get more throughput
  - Continued expression review/tidying up to reduce redundancy of calculations
  - Buy a bigger / faster server and test ahead of time in the cloud what’s possible with respect to runtime reductions
Update on usability issue voting and Google docs for telecommute and transit pass models
- Potential improvements list wiki page now linked to issues
- Folks vote (thumbs-up) favorite 3 by 4/8
- We'll then work through the list, implementing what we can with the task budget
- Telecommute google doc here and comments due 4/8
- Joel to work on transit pass data analysis soon
- Transit pass google doc here and will set review data once we get more info from Joel on the data analysis
Update on non-mandatory tour scheduling enhancements to speed it up
- Segmented by tour purpose to reduce redundant calculations
- Added support for ALTS PREPROCESSOR to calculated shift variables to reduce redundant calculations
- See example semcog non_mandatory_tour_scheduling.yaml
- SEMCOG to officially integrate next
Update on estimation mode enhancements
- Pull Request #400 is just about ready
- Need to finish the last few notebooks and re-implement the regression testing on Travis to make sure these tools don’t break due to future updates (or at least notify us if they do break, so they can be maintained).
- PR addresses issue 398 fixed as well
- I'll review and soon integrate for the upcoming release