Thanks.
I think I might now be seeing what you are saying. Sorry to be so stupid. I
found this count stuff to be mind boggling.
IntSetArgs s((LPTYPER)bp.MaxBit);
for (LPTYPER i = 0; i < (LPTYPER)bp.MaxBit;
i++) {
s[i] =
IntSet((LPTYPER)bp.Bits[i], (LPTYPER)bp.Bits[i]);
}
count(*this, b, s, IPL_DOM);
I guess I was feeling I was using an overly more general mechanism with
variables for counts when I have constants for counts. With the sets I am still
using something which allows much more general situations but since it’s
constants it might be optimized away.
So I assume this would be the recommended way to code this?
Neill.
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
________________________________
From: Christian Schulte <[email protected]>
Sent: Monday, March 12, 2018 9:31:36 AM
To: Neill Clift; [email protected]
Subject: RE: Extra level of variables needed for count?
No, the point is to not use variables, you can use sets with a single element
instead. Christian
--
Christian Schulte, https://chschulte.github.io/
Professor of Computer Science, KTH, [email protected]<mailto:[email protected]>
Expert Researcher, RISE SICS,
[email protected]<mailto:[email protected]>
From: Neill Clift [mailto:[email protected]]
Sent: Monday, March 12, 2018 17:30
To: Christian Schulte <[email protected]>; [email protected]
Subject: RE: Extra level of variables needed for count?
OK thanks for that. This makes the code simpler but I do still have to make a
set of variables to contain the multiplicities (the v’s).
Of course they immediately become assigned to a single value. Would it be right
in assuming the cost of that on the model is very small?
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
________________________________
From: Christian Schulte <[email protected]<mailto:[email protected]>>
Sent: Monday, March 12, 2018 2:31:26 AM
To: Neill Clift; [email protected]<mailto:[email protected]>
Subject: RE: Extra level of variables needed for count?
Hi,
I think you stopped reading a little too early. MPG says that you can also use
integer sets instead of variables.
Then, in your example you do not need x and c, just pass b and v directly!
IntVarArray is automatically casted to IntVarArgs.
Cheers
Christian
--
Christian Schulte, https://chschulte.github.io/
Professor of Computer Science, KTH, [email protected]<mailto:[email protected]>
Expert Researcher, RISE SICS,
[email protected]<mailto:[email protected]>
From: [email protected]<mailto:[email protected]>
[mailto:[email protected]] On Behalf Of Neill Clift
Sent: Saturday, March 10, 2018 20:37
To: [email protected]<mailto:[email protected]>
Subject: [gecode-users] Extra level of variables needed for count?
Hi,
I want to restrict the values of an array to members of a multiset. This is a
bit like distinct but can have repeated values.
So for example I want the values of b[0..7] to come from the multiset
{5,5,5,4,3,2,1,0}. The b’s are essentially a permutation of the multiset
Count seems to be the way to achieve this but I have to add a whole new set of
variables (the v’s below) that contain the counts of the multiplicities.
I cut out a bunch of stuff that’s not relevant to the code below so I hope it
still makes sense.
bp.MaxBit is the number of distinct values in the multiset. And bp.Bits[i] is
the multiplicity for the multiset value i.
Is this the expected way to do what I am trying to do here?
Thanks.
Neill.
public:
IntVarArray b;
public:
PartialOrderSort(LPTYPER n, BIT_PATTERN &bp, LPTYPER TopIndex) :
b(*this, n, 0, TopIndex)
{
IntVarArgs x(n);
IntVarArgs c((LPTYPER)bp.MaxBit);
for (int i = 0; i < n; i++) {
x[i] = b[i];
}
IntVarArray v(*this, (LPTYPER)bp.MaxBit, 0, n -
1);
for (int i = 0; i < bp.MaxBit; i++) {
c[i] = v[i];
rel(*this, v[i] ==
(LPTYPER)bp.Bits[i]);
}
count(*this, x, c, IPL_DOM);
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
_______________________________________________
Gecode users mailing list
[email protected]
https://www.gecode.org/mailman/listinfo/gecode-users
