Re: [UrbanSim-Users] Own identifiers: zone_id, grid_id, group_id, etc.

Mark,

I can handle the first part of your question:

The error comes due to a mismatch between grid_id in gridcells and
grid_id in households. I assume there are some values in the households
table that do not exist in the gridcells table. Please check.

It should not be connected to the fact that there is a big difference
between the max and min of your zone_id. However, the code will run more
efficiently, if the difference is small (about twice of the number of
elements in the table). This fact applies to any dataset.

Hana

On Tue, 25 Sep 2007, Mark Kryvobokov wrote:

> Hello!
>
> We still use UrbanSim version 4.0 (though we are thinking about the updating).
>
> We have a question about the creation of our own identifiers. We tried to use our own zone_id (unique integer values with the range of 10050000 to 693890604) . We changed the Eugene zone_id values with our zone_id values in zones and gridcells tables. We changed also from_zone_id and to_zone_id values in travel_data table. After that simulation running failed while executing the Commercial Employment Location Choice Model. This is a part of the traceback message:
>
>
> File "C:\MyNew\projects\OPUS\opus-4.0\urbansim\gridcell\population.py", line 34, in compute
>
> return self.get_dataset().sum_dataset_over_ids(households, self.hh_persons)
>
> File "C:\MyNew\projects\OPUS\opus-4.0\opus_core\dataset.py", line 1118, in sum_dataset_over_ids
>
> return self.aggregate_dataset_over_ids(dataset, "sum", attribute_name, constant)
>
> File "C:\MyNew\projects\OPUS\opus-4.0\opus_core\dataset.py", line 1148, in aggregate_dataset_over_ids
>
> return self.aggregate_over_ids(dataset_id_values[used], values, function)
>
> File "C:\MyNew\projects\OPUS\opus-4.0\opus_core\dataset.py", line 1112, in aggregate_over_ids
>
> raise StandardError, "Unknown function " + function + " or error occured during evaluation."
>
> StandardError: Unknown function sum or error occured during evaluation.
> We suppose that the reason or the error is a big difference between max and min values of zone_id. Could somebody confirm this and/or explain why it is so?
>
> Our next question is about group_id. In development_type table for Eugene, we see min_sqft and max_sqft for different development types. Is there some rule according to which a gridcell should belong to e.g. industrial or commercial group if there are different types of development? Can we formulate our own rules?
>
> Thank you in advance,
> Mark and Philippe
Received on Wed Sep 26 2007 - 16:58:54 PDT