Brian,
The order of the constraints in the table doesn't matter. For a given
gridcell, it'll first match constraints in development _constraints table
that are applicable to it according to attributes with matched names in both
tables" (plan_type_id, is_in_wetland, etc), then the most restrictive rule,
i.e. the highest minimum values and the lowest maximum values among
applicable constraints, applies for each type of restrictions (units,
commercial_sqft and industrial_sqft).
The implementation of the constraints is in the
urbansim/datasets/gridcell_dataset.py, which is called in the capacity
variables (urbansim.gridcell.developable_maximum_commercial_sqft and
developable_minimum_commercial_sqft, etc) of the development project
location choice model.
Hope this helps.
Liming.
On Fri, May 16, 2008 at 11:25 AM, Brian Miles <Brian.Miles_at_uvm.edu> wrote:
>
> Hello,
>
> We're working on some scenarios and we need to understand how
> development constraints are evaluated so that we can interpret the
> results we are seeing.
>
> The documentation in the manual for this is thin. One thing we are
> wondering is, does the order in which constraints are listed in the
> table have any bearing on what development is allowed in a given
> gridcell?
>
> Could you point out where in the location choice model code
> development constraints are evaluated?
>
> Thanks,
>
> Brian
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Received on Tue May 20 2008 - 12:19:22 PDT
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