[UrbanSim-Users] HLCM, use sample with replacement

Hello,

We're seeing the following error in the seventh iteration of our HLCM:

HLCM chunk 4 out of 12.: started on Thu Mar 06 08:07:45 2008
                    Number of agents in this chunk: 56
                    urbansim.gridcell.vacant_residential_units
                         
urbansim.gridcell.number_of_households...........0.0 sec
                    urbansim.gridcell.vacant_residential_units:
completed...0.0 sec
                    Available capacity: 0 units.
                    Sampling locations ...
                    WARNING: weight_array sums to 0 or less
                    WARNING: weight array dosen't have enough non-zero
counts, use sample with replacement
                    WARNING: prob_array doesn't sum up to 1, and is
normalized. Sum: 0.0
                HLCM chunk 4 out of 12.:
completed.......................0.0 sec

(full stack trace is below)

We were able to get our simulation past this error and to run beyond
the seventh year, all the way to the 10th, by adding five residential
units to all gridcells with non-zero residential units.

But we don't know what the error "weight array dosen't have enough non-
zero counts, use sample with replacement"--thrown by
opus_core.samplers.weighted_sampler--means. It seems to be telling us
to try setting some option, but I'm not sure.

How should we interpret this error?

Thanks,

Brian

  Number of unplaced agents: 45 (in 2 iterations)
                HLCM chunk 3 out of 12.:
completed.......................0.6 sec
                HLCM chunk 4 out of 12.: started on Thu Mar 06
08:07:45 2008
                    Number of agents in this chunk: 56
                    urbansim.gridcell.vacant_residential_units
                         
urbansim.gridcell.number_of_households...........0.0 sec
                    urbansim.gridcell.vacant_residential_units:
completed...0.0 sec
                    Available capacity: 0 units.
                    Sampling locations ...
                    WARNING: weight_array sums to 0 or less
                    WARNING: weight array dosen't have enough non-zero
counts, use sample with replacement
                    WARNING: prob_array doesn't sum up to 1, and is
normalized. Sum: 0.0
                HLCM chunk 4 out of 12.:
completed.......................0.0 sec
            Running Household Location Choice Model (from
urbansim.models.household_location_choice_model): completed...18.8 sec
        Simulate year 1997: completed.............................1
min, 3.7 sec
        Closing log file: C://urbansim_cache
\run_63.2008_03_06_07_59\year_1997_log.txt
    Starting simulation for year 1997: completed..................1
min, 3.7 sec
Start simulation run: completed...................................1
min, 3.7 sec
Closing log file: C://urbansim_cache
\run_63.2008_03_06_07_59\run_multiprocess.log
Traceback (most recent call last):
  File "C:\opusworkspace-svn\urbansim\model_coordinators
\model_system.py", line 532, in <module>
    s.run(resources)
  File "C:\opusworkspace-svn\urbansim\model_coordinators
\model_system.py", line 135, in run
     
write_datasets_to_cache_at_end_of_year
=write_datasets_to_cache_at_end_of_year)
  File "C:\opusworkspace-svn\urbansim\model_coordinators
\model_system.py", line 299, in _run_year
    self.vardict[outputvar] = self.do_process(locals())
  File "C:\opusworkspace-svn\urbansim\model_coordinators
\model_system.py", line 377, in do_process
    return eval(ev)
  File "<string>", line 1, in <module>
  File "C:\opusworkspace-svn\opus_core\model.py", line 48, in
logged_run_method
    results = run_method(*req_args, **opt_args)
  File "C:\opusworkspace-svn\opus_core\configurable.py", line 38, in
config_run_method
    results = run_method(*req_args, **opt_args)
  File "C:\opusworkspace-svn\urbansim\models
\agent_location_choice_model.py", line 88, in run
    agents_index[unplaced], chunk_specification, debuglevel=debuglevel)
  File "C:\opusworkspace-svn\urbansim\models
\location_choice_model.py", line 123, in run
    debuglevel=debuglevel)
  File "C:\opusworkspace-svn\opus_core\choice_model.py", line 142, in
run
    specification=specification, coefficients=coefficients)
  File "C:\opusworkspace-svn\opus_core\chunk_model.py", line 72, in run
    dataset, **kwargs).astype(result_array_type)
  File "C:\opusworkspace-svn\urbansim\models
\agent_location_choice_model.py", line 101, in run_chunk
    result = LocationChoiceModel.run_chunk(self, agents_index,
agent_set, specification, coefficients)
  File "C:\opusworkspace-svn\urbansim\models
\location_choice_model.py", line 144, in run_chunk
    choices = ChoiceModel.run_chunk(self,agents_index, agent_set,
specification, coefficients)
  File "C:\opusworkspace-svn\opus_core\choice_model.py", line 152, in
run_chunk
    index = self.get_choice_index(agent_set, agents_index, agentsubset)
  File "C:\opusworkspace-svn\urbansim\models
\location_choice_model.py", line 270, in get_choice_index
    weight=self.weights, resources=self.run_config)
  File "C:\opusworkspace-svn\opus_core\configurable.py", line 38, in
config_run_method
    results = run_method(*req_args, **opt_args)
  File "C:\opusworkspace-svn\opus_core\samplers\weighted_sampler.py",
line 103, in run
    replace=replace, return_indices=True )
  File "C:\opusworkspace-svn\opus_core\sampling_toolbox.py", line 284,
in prob2dsample
    cum_prob = ncumsum(p_array)
  File "C:\opusworkspace-svn\opus_core\misc.py", line 515, in ncumsum
    str(prob_array.sum(axis=axis, dtype=dtype))
ValueError: The probability array must sum up to 1. It is -1.#IND
Running UrbanSim for year 1997 in new process: completed..........1
min, 5.5 sec
Traceback (most recent call last):
  File "start_run.py", line 84, in <module>
    run_manager.run_run(config, run_as_multiprocess =
run_as_multiprocess)
  File "C:\opusworkspace-svn\opus_core\services\run_server
\run_manager.py", line 183, in run_run
    raise SimulationRunError
opus_core.services.run_server.run_manager.SimulationRunError
Received on Thu Mar 06 2008 - 10:11:16 PST