[Scip] Call to adjustedUb in SCIPvarChgUbOriginal causing solve failures

[Gerald Gamrath]

Hi Fergal,

SCIP has its own infinity value, which is per default 1e+20. Every 
number larger than that is treated as infinity and just set to 1e+20. If 
you really need larger numbers, you have to change the SCIP parameter 
"numerics/infinity" to something larger, but actually, 1e+98 is the 
highest possible number. As far as I know, the infinity value in SCIP 
was always 1e+20, so it should not have worked in older versions, 
either. Perhaps you mixed it up with Soplex, where the infinity value is 
1e+100?

Besides, the method SCIPvarChgUbOriginal() is for internal use only. You 
should only use methods stated in scip.h and pub_*.h. The correct method 
would be SCIPchgVarUb(), given in scip.h, which - depending on the stage 
of SCIP - also changes the original bound (when you are in the problem 
creation stage). In all other stages, you must not change the original 
bound, anyway.

Best,
Gerald

Am 03.05.2011 13:32, schrieb fergal mohan:
> Hi all, I've recently updated the Microsoft .NET wrapper that I wrote a couple
> of years ago to allow .NET Applications so that it could be used SCIP 2.0 and
> Soplex 1.5. I restructured the projects to use the new Developer Studio Solution
> files that were made available (thanks Wei Huang) and after fixing up a few
> things that I was expecting all seems to be working as expected apart from one
> problem. When I try to set an upper bound using SCIPvarChgUbOriginal() to 1e100
> the new call to adjustedUb() overrides the incoming value and restricts the
> upper bound to 1e20. This causes my previously working solve to now fail. I'm
> not sure if it's a case that I have previously been relying on something that
> was incorrect in the older versions or if this is a "real" issue with the
> current SCIP version. I can supply more details on my test if it helps but at
> the macro level I just wanted to first check with the the mailing list colective
> wisdom as to whether the adjustedUb() interaction is kosher? Any insights out
> there ?
> Fergal 
>
> _______________________________________________
> Scip mailing list
> Scip at zib.de
> http://listserv.zib.de/mailman/listinfo/scip