[gecode-users] CSPs with bulky static data

[Torsten Anders]

Dear Christian and Guido,

Thank you both very much for your incredibly quick response. This is 
indeed very encouraging to hear! Here is a related question.

Currently, my bulky data structure in the CSP simply contains the 
constrained variables. As the whole data is copied, the data structure 
always reflects what is currently known about the variable values. In 
the CSP definition, my constraint application mechanisms process the 
data structure to know which constraint is applied to which set of 
variables. Also my distribution (branching) strategies traverse this 
data structure, exploit the current value of variables and what the 
variables mean in the data structure to decide which variable to 
distribute next.

How would I reproduce something similar in Gecode such that I leave the 
bulky static data outside the computational space? I need (i) the data 
which is outside the space, (ii) the variables inside the space, and 
(iii) also some bidirectional linking between both. For instance, every 
variable might be 'tagged' with a unique integer such that I can access 
the variable when I have the integer and vice versa (e.g. to get the ID 
for some variable, every variable is put in some simple data structure 
containing the variable and the ID; to get the variable for some ID, 
all variables are also stored in an array).

This linking would then allow to again traverse the data structure as 
if it contains the variables, although the data structure is actually 
outside and the variables are inside the space. I would perform such a 
traversal to apply my constraints to the variables. Moreover, my Gecode 
branching strategy would process a sequence with all the simple data 
structures containing the variable and the ID (i.e. the branching 
strategy has access to the present value of the variables and the data 
outside the space to decide which variable to distribute next).

Does such an approach sound plausible for you?

Thank you very much indeed!

Best,
Torsten

--
Torsten Anders
Sonic Arts Research Centre • Queen's University Belfast
Frankstr. 49 • D-50996 Köln
Tel: +49-221-3980750
http://www.torsten-anders.de
http://strasheela.sourceforge.net