[gecode-users] Fwd: Re: propagation consistency of count (single value) constraint

[Christian Schulte]

Hi Kish,

I just fixed the bug in the trunk: it was a bug in posting the constraint
(and only for ICL_BND). Unfortunately, the tests had not been adapted to the
fact that both ICL_BND and ICL_DOM is supported. That's also fixed.

Cheers
Christian

--
Christian Schulte, www.gecode.org/~schulte 
Professor of Computer Science, KTH, cschulte at kth.se
Expert Researcher, SICS, cschulte at sics.se

-----Original Message-----
From: users-bounces at gecode.org [mailto:users-bounces at gecode.org] On Behalf
Of Kish Shen
Sent: Sunday, September 6, 2015 08:12 AM
To: users at gecode.org
Subject: [gecode-users] Fwd: Re: propagation consistency of count (single
value) constraint


I think I didn't send this to the mailing list, so here it is...

-------- Forwarded Message --------
Subject: Re: [gecode-users] propagation consistency of count (single
value) constraint
To: cschulte at kth.se
References: <55DE1FB2.90108 at cisco.com> <55DF3132.8080407 at cisco.com>
<00ba01d0e4a5$32dd8720$98989560$@kth.se>
From: Kish Shen <kisshen at cisco.com>
Message-ID: <55EBC8B7.3020207 at cisco.com>
Date: Sun, 6 Sep 2015 06:01:43 +0100
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101
Thunderbird/38.2.0
In-Reply-To: <00ba01d0e4a5$32dd8720$98989560$@kth.se>
Content-Type: text/plain; charset="windows-1252"; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0

On 01/09/2015 11:58, Christian Schulte wrote:
> Hmm, I had a quick look at the code and I think it should rewrite to 
> the int/int case. I am travelling right now, so I will look more 
> carefully when I am back in a week or so.
>

Hi Christian,

I looked at the program more closely, and it seems that the reason for the
apparent better performance with ICL_BND is because the constraint succeeds
when it is violated. The following does not fail when posted with ICL_BND:

count(home, x, y, IRT_GR, z, ICL_BND)

x = {5,5,5,5,5,5,5}, y = 1, z = 0

y and z are IntVars with singleton domains.

This succeeds when posted with x set to all 5s, or as variables which are
then labelled to 5 during the search.

The constraint fails when posted with ICL_DOM.

Cheers,

Kish






_______________________________________________
Gecode users mailing list
users at gecode.org
https://www.gecode.org/mailman/listinfo/gecode-users