I am working on a problem when I use a predicate cumulatives/[2,3]. But I get very poor performance when I try to combine this with minimizeinlabeling
I have the following demo. 10, all with a duration of 1, 4 cars, all with a capacity = 1. My goal is to minimize the total time, i.e. minimize(maximum(Es)):
:- use_module(library(clpfd)).
:- use_module(library(lists)).
go( Ss, Es, Ms, Tm, Lab ) :-
Ss = [S1, S2, S3, S4,S5,S6,S7,S8,S9,S10], %Starttimes
Es = [E1, E2, E3, E4,E5,E6,E7,E8,E9,E10], %Endtimeds
Ms = [M1, M2, M3, M4,M5,M6,M7,M8,M9,M10], %MachineIds
domain(Ss, 1, 20),
domain(Es, 1, 20),
domain(Ms, 1, 10),
%All task has duration = 1
Tasks = [
task( S1, 1, E1, 1, M1 ),
task( S2, 1, E2, 1, M2 ),
task( S3, 1, E3, 1, M3 ),
task( S4, 1, E4, 1, M4 ),
task( S5, 1, E5, 1, M5 ),
task( S6, 1, E6, 1, M6 ),
task( S7, 1, E7, 1, M7 ),
task( S8, 1, E8, 1, M8 ),
task( S9, 1, E9, 1, M9 ),
task( S10, 1, E10, 1, M10 )
],
%All machines has resource capacity = 1
Machines = [
machine( 1, 1 ),
machine( 2, 1 ),
machine( 3, 1 ),
machine( 4, 1 )
],
cumulatives(Tasks, Machines, [bound(upper)] ),
maximum( MaxEndTime, Es ),
%Make the list of options to pass to the labeling predicate
append( [ [minimize(MaxEndTime)], [time_out( Tm, _)], Lab ], LabOpt ),
%The variables to lable:
append([Ms, Ss ], Vars),
labeling( LabOpt, Vars).
If I run this now and resolve within 1 second, I get:
| ?- go( S, E, M, 1000, []).
E = [2,3,4,5,6,7,8,9,10,11],
M = [1,1,1,1,1,1,1,1,1,1],
S = [1,2,3,4,5,6,7,8,9,10] ?
those. all tasks were scheduled to run on machine 1
I need to start the solver within 30 seconds before I see any signs of minimization:
| ?- go( S, E, M, 30000, []).
E = [2,3,4,5,6,7,8,9,10,2],
M = [1,1,1,1,1,1,1,1,1,2],
S = [1,2,3,4,5,6,7,8,9,1] ?
If I work for 60 seconds, I will start to get acceptable results:
| ?- go( S, E, M, 60000, []).
E = [2,3,4,2,3,4,2,3,4,2],
M = [1,1,1,2,2,2,3,3,3,4],
S = [1,2,3,1,2,3,1,2,3,1] ?
I feel this has been going on for too long. Any comments on why this took so long?