Re: [UrbanSim-Users] Household location choice estimation

Brian,

> Perhaps I am confused about the function of the estimation procedure. I
> understand that the number of movers and the unplaced agents are derived
> by the Household Relocation Model, but how do these movers and unplaced
> agents relate to the records in the households_for_estimation table?
> More specifically, how can there be more movers / unplaced agents than
> there are records in the households_for_estimation table?

In the default estimation behavior we try to create the same situation
as in the simulation of HLCM which runs in 12 chunks (corresponding to
12 months). So we let the HRM choose movers (from the whole household
set) and unplace 1/12 of them (randomly chosen), in order to have
similar vacancy as in the simulation. Households in
households_for_estimation are unplaced too, but after the their location
is captured and passed to the estimation procedure. Note that the
households_for_estimation table is by default internally attached to the
households table, in order to have information about the whole population.

As I said, this behavior is the default one and can be changed. You can
look at

urbansim/configurations/household_location_choice_model_configuration_creator.py

I just added comments to the arguments (so please get the newest file
from svn). You can then experiment with changing the default values here.

> Perhaps too I
> don't understand correctly what the dependent variable is that we are
> modeling. I thought the estimation procedure evaluated the location
> choice for each household in the household_for_estimation table compared
> to the attributes of the other records in the choice set. Is this correct?

It is correct.

I hope this clarifies it a little bit.

Hana
Received on Mon Mar 03 2008 - 15:14:34 PST