Re: [Help-glpk] [Fwd: memory]

[Nigel Galloway]

Do you mean GLPK is Solver and CMPL is preprocessor?

What do you mean by stronger than expected? What happens at 29 and 31.
Draw a graph of times between 15 and 30. I would say that, if the graph
is smooth then the value for 30 is exactly as expected. If its smooth to
29 then discontinuous to 30 it is unexpected.

-- 
  Nigel Galloway
  address@hidden


On Friday, November 25, 2011 12:11 AM, "Andrew Makhorin" <address@hidden>
wrote:
> -------- Forwarded Message --------
> From: Ronald Wolthoff <address@hidden>
> To: address@hidden
> Subject: memory
> Date: Thu, 24 Nov 2011 09:44:57 -0500
> 
> Hello,
> 
> I'm using GLPK in combination with CMPL and I encounter some issues with 
> the time required for preprocessing. My problem has 2N^2 rows and 2N^4 
> columns (real variables, less than 1% non-zeros). When I run the problem 
> for N=15 (450 rows, 101250 columns), the preprocessing takes 
> approximately 1 minute and the solver 3 seconds, which is great. When I 
> use N=30 instead (1800 rows, 1,620,000 columns) , the solving time goes 
> up to a few minutes, which is still great, but the preprocessing time 
> explodes to something like 9 hours. Although the problem is fairly 
> large, this increase seems stronger than expected. Is there a way I 
> could reduce the preprocessing time, e.g. by allocating more memory to 
> the program?
> 
> Many thanks,
> 
> Ronald
> 
> 
> 
> 
> _______________________________________________
> Help-glpk mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/help-glpk
> 

-- 
http://www.fastmail.fm - Same, same, but different...