[UrbanSim-Users] location choice models: problem with sampling alternatives

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
Received on Fri May 02 2008 - 11:07:48 PDT