Re: [Minion-general] switches

[Chris J. <ch...@bu...>]

2008/6/17 Tias Guns <tia...@cs...>:
> On Thu, 12 Jun 2008 21:53:25 +0200, Chris Jefferson <ch...@bu...>
> wrote:
>
>> Thank you for your comments!
>>
>> Fortunately, in the next couple of weeks Minion's documentation should
>> improve hugely, as a Constraint Programming Summer School is being
>> held in St. Andrews ( http://www-circa.mcs.st-and.ac.uk/cpss2008/ ) in
>> which we will be using Minion extensively. We will use your comments
>> when making these changes!
>
> I'll be attending that summer school, that's why I'm already testing it out
> a bit on my own models : )

Then I shall see you there!


>
>> -varorder is another powerful tool, but can be difficult to tune. Look
>> out for overtuning for one or two instances. Useful values to try are:
>>
>> static (default) - goes in the order you list in the 'VARORDER' section.
>> conflict - which tries to search variables which have previously
>> caused problems.
>> sdf - Generally considered the "standard" order most people use.
>
> Interestingly, I've compared with gecode for some datasets, and minion is
> slightly better than gecode if I use the input order as variable ordering.
> If i take 'degree_max' (take variable which is most constrained) then gecode
> becomes significantly faster.
> Would your system allow for a variable ordering similar to 'degree_max' ?
> I'm interested to see if minion would outperform gecode, and how it would
> scale into 10 000's of variables and constraints.

If you compile minion with the option 'WDEG', which you do as follows:

make minion MYFLAGS="-DWDEG"

Then the variable ordering will gain the option 'wdeg', which I
believe does something similar to this. The reason this is not turned
on by default is that the code to implement it slows Minion down even
when it in not in use.

Chris