Skip to content

Lower default threshold for skipped failed choices to 0.1% #1063

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
i-am-sijia wants to merge 2 commits into
base: main
Choose a base branch
from
+9 −4
Open

Lower default threshold for skipped failed choices to 0.1% #1063

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
abed627
change default to 0.1% hh allowed to be skipped
i-am-sijia Apr 2, 2026
12fc355
[skip ci] update doc
i-am-sijia Apr 2, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion activitysim/core/configuration/top.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -790,7 +790,7 @@ def _check_store_skims_in_shm(self):
.. versionadded:: 1.6
"""

fraction_of_failed_choices_allowed: float = 0.1
fraction_of_failed_choices_allowed: float = 0.001
"""
Threshold for the fraction of households that can be skipped before failing the model run,
used in conjunction with `skip_failed_choices`.
Expand Down
11 changes: 8 additions & 3 deletions docs/users-guide/ways_to_run.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -312,6 +312,11 @@ For interaction_simulate models, users can manually specify trace IDs to perform
Users can configure ActivitySim to not skip failed choices by setting the
``skip_failed_choices`` option to ``False`` in the settings file. When this option is disabled, the system will fall back to
using the legacy ``overflow_protection`` mechanism to handle such cases. Specifically, if the computed utilities lead to zero or infinite exponentiated values,
overflow protection will adjust the utilities to prevent numerical overflow during exponentiation and arbitarily making a choice.
No loggings will be made for these cases. When ``skip_failed_choices`` is enabled,
ActivitySim will not use the legacy ``overflow_protection`` mechanism to handle failed choices.
the legacy ``overflow_protection`` will adjust the utilities to prevent numerical overflow during exponentiation and arbitarily making a choice, however, no loggings will be made for these cases.
When ``skip_failed_choices`` is enabled, ActivitySim will not use the legacy ``overflow_protection`` mechanism to handle failed choices.

.. note::
When an agency turns on ``skip_failed_choices`` for the first time in an existing ActivitySim implementation,
warning messages may appear in the log for failed choices that were previously handled silently by the legacy ``overflow_protection`` mechanism.
These warnings are expected and reflect the change in behavior: failed choices are now explicitly skipped and traced rather than silently handled.
In some cases, model runs may crash if the number of skipped failed choices exceeds the configured ``fraction_of_failed_choices_allowed`` threshold.