[Osi] Bug in Osi?

[Horand Gassmann]

Hi,

I am trying to solve a small aggregate planning model. (AMPL model and  
data files attached.) The LP relaxation works fine, but when I add an  
integrality constraint on the first set of variables (number_workers),  
I get an assert error:

../../../../Osi/src/Osi/OsiPresolve.cpp:507: virtual void   
OsiPresolve::postsolve(bool): Assertion `status !=   
CoinWarmStartBasis::atUpperBound || originalModel_->getColUpper()[i] <  
  infty' failed.

What causes the error is unclear to me. I do not provide a starting  
basis, so I wouldn't expect the presolver to even go there. Is this a  
bug? Does the presolver require finite upper bounds? Any ideas?

Thanks

gus
-------------------------------------------------------

Horand I. Gassmann, Professor

Kenneth C. Rowe School of Business, Dalhousie University
6100 University Avenue, PO Box 15000
Halifax, Nova Scotia, Canada, B3H 4R2
ph. (902) 494-1844
fax (902) 494-1107

http://myweb.dal.ca/gassmann/


----- End forwarded message -----


-------------------------------------------------------

Horand I. Gassmann, Professor

Kenneth C. Rowe School of Business, Dalhousie University
6100 University Avenue, PO Box 15000
Halifax, Nova Scotia, Canada, B3H 4R2
ph. (902) 494-1844
fax (902) 494-1107

http://myweb.dal.ca/gassmann/
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