Brian,
This means the array used as weight in the weighted sampling contains
negative (less than 0) values. In most case, the weight array is from
vacant units attribute, which could contain negative values if more
households are allocated to gridcells/buildings than their existing
units in the baseyear. In which model do you encounter these
warnings?
I tried to run eugene sample project for both estimation and
simulation, and I didn't seem to get any of similar warnings.
Liming.
On Fri, May 2, 2008 at 11:07 AM, Brian Miles <Brian.Miles_at_uvm.edu> wrote:
>
> Hello,
>
> After recently upgrading to the latest development version of OPUS, I
> noticed the following messages that appear when our location choice
> models run:
>
> WARNING: Problem with sampling alternatives.
> some values of rows [ 929 1797 2590 3657
> 3757 5265 7923 10166 12310] in weight_array are less than 0
>
> The locations differ across models, and sometimes there are hundreds
> reported in the message.
>
> I thought this was a strange message, so I decided to compare the
> output of our model to the Eugene example. I found similar "errors"
> in the Eugene model.
>
> My questions are: 1) what does this message mean; and 2) does it
> indicate a problem that needs to be corrected?
>
> Thanks,
>
> Brian
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Received on Fri May 02 2008 - 12:23:19 PDT
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