[Os-project-managers] NaN in xs:double (OSrL)

[Kipp Martin]

Hi Gus:

So I guess there are places were we instantiate an object and we set 
data members equal to NaN. Is that correct?
>> It seems to me that by definition of an optimal, indeed even feasible
>> solution, cannot contain a NaN.  If the solver does return NaN my first
>> inclination is in the <optimization> child <status> set type = "error"
>> and under description say "solver returned a NaN."  In  such a case we
>> would not print a <solution>. I would argue that having a NaN as a
>> solution value is an oxymoron.
> 
> But even then, I think, the diagnostics would be helped greatly if we 
> provide tools to *pinpoint* where the NaN occurred. We allow NaN to be 
> provided as a *starting value*, so why not as a terminating value? We 
> seem to be breaking the symmetry here.

But we DON'T provide the value to the solver correct? Don't we use it as 
a  place holder so we can skip over that initial value? I see this as 
quite different from reporting it in a solution.

Cheers


> 
> Just my Can$ 0.02
> 
> Cheers
> 
> gus
> 


-- 
Kipp Martin
Professor of Operations Research
and Computing Technology
Booth School of Business
University of Chicago
5807 South Woodlawn Avenue
Chicago, IL 60637
773-702-7456
kmartin at chicagobooth.edu
http://www.chicagobooth.edu/faculty/bio.aspx?person_id=12825325568
http://projects.coin-or.org/OS