Re: [UrbanSim-Users] AutoOwnershipChoiceModel

Mark,

An interaction variable used in a choice model gives you a 2D array
where one dimension is the number of agents, the other dimension
corresponds to the number choices. I'm not sure, how do you want to use
a household_x_gridcell variable in this context. Do you have a specific
example?

Your results of getting singular matrix might be due to the fact, that
you're using a choice set that includes 0. The ChoiceModel doesn't like
that (see http://www.urbansim.org/docs/opus-userguide/node130.html). In
the newest developer version of urbansim you could specify an expression
for choice_attribute_name, e.g. 'carsplus1 = household.cars + 1'. If you
have an older version, you need to add an additional attribute to the
household table that would shift the number of cars by a constant, so
that you don't have a zero there.

Hana

Mark Kryvobokov wrote:
>
>
> Hello,
>
> We are trying to create the Auto Ownership Choice Model. When we have
> the independent variables from the 'household' dataset only, we obtain a
> singular matrix. It seems that it's not enough to be limited to the
> household attributes. We are trying to use the interaction variables
> from the 'household_x_gridcell' dataset, but we get the error:
>
> "ValueError: different dataset names for variable and dataset or a
> component".
>
> In the auto_ownership_choice_model_configuration_creator we specified:
> agent_set = Str('household') and choice_attribute_name = Str('cars'),
> where 'cars' is an attribute from the 'household' dataset. We also have
> choice_set = ListInt([0,1,2]). So we get the interaction dataset
> 'household_x_choice' and we seem to be limited to the variables that are
> part of that dataset.
>
> Is it possible to use variables from 'household_x_gridcell' in this case
> where there is already an interaction with another dataset which is choice?
>
> Thank you,
>
> Mark
>
>
>
>
>
>
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Received on Wed May 14 2008 - 13:31:30 PDT