Pydantic validator crashing model when logsum calculation done with MNL model #908
Description
Describe the bug
When trying to run SANDAG's airport access models using ActivitySim version 1.3.2, there was a crash in nonmandatory tour destination that happened when evaluating the logsums using the (dummy) tour mode choice MNL model. This was caused by the validator requiring the nest_spec to be either a LogitNestSpec object or a dictionary. However, if one looks at the function that gets the nest_spec, it returns None if the model is set to be MNL. This is later used as a flag to be MNL or NL when evaluating utilities, so having the nest_spec as a None type shouldn't be causing a crash.
To Reproduce
Steps to reproduce the behavior:
- Using ActivitySim v1.3.2, run a destination choice model that calculates logsums with a MNL logit model such as tour mode choice in SANDAG's airport access models (NOTE--if using that example some other configs may need to be adjusted to account for changes made in version 1.3).
- The model should fail due to a ValidationError.
Expected behavior
The logsums should have properly been evaluated without needing to check that the nonexistent nesting structure was valid.
Screenshots
Full traceback from logfile:
Traceback (most recent call last):
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\core\mp_tasks.py", line 1098, in mp_run_simulation
run_simulation(state, queue, step_info, resume_after, shared_data_buffer)
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\core\mp_tasks.py", line 1048, in run_simulation
raise e
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\core\mp_tasks.py", line 1043, in run_simulation
state.run.by_name(model)
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\core\workflow\runner.py", line 347, in by_name
self._obj._context = run_named_step(
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\core\workflow\steps.py", line 83, in run_named_step
step_func(context, **kwargs)
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\core\workflow\steps.py", line 367, in run_step
outcome = error_logging(wrapped_func)(state, *args, **kwargs)
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\core\workflow\steps.py", line 46, in wrapper
return func(*args, **kwargs)
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\abm\models\non_mandatory_destination.py", line 82, in non_mandatory_tour_destination
choices_df, save_sample_df = tour_destination.run_tour_destination(
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\abm\models\util\tour_destination.py", line 856, in run_tour_destination
location_sample_df = run_destination_logsums(
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\abm\models\util\tour_destination.py", line 660, in run_destination_logsums
logsums = logsum.compute_location_choice_logsums(
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\abm\models\util\logsums.py", line 170, in compute_location_choice_logsums
nest_spec = simulate.eval_nest_coefficients(nest_spec, coefficients, trace_label)
File "\\JUPITER\ABM\user\jflo\repos\asim132\activitysim\core\simulate.py", line 470, in eval_nest_coefficients
nest_spec = LogitNestSpec.model_validate(nest_spec)
File "C:\Anaconda3\envs\asim_132\lib\site-packages\pydantic\main.py", line 596, in model_validate
return cls.__pydantic_validator__.validate_python(
pydantic_core._pydantic_core.ValidationError: 1 validation error for LogitNestSpec
Input should be a valid dictionary or instance of LogitNestSpec [type=model_type, input_value=None, input_type=NoneType]
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