[Scip] scipoptsuite-3.0.0 and ziboptsuite2.1.1 give different results

[Hélène Toussaint]

Dear all,

I have recently upgraded my ziboptsuite version from 2.1.1 to 3.0.0.. I 
run a column generation program using version 2.1.1 and version 3.0.0. 
and I obtained different results (I have changed nothing in my code).

During the column generation, I have written one of my pricing problems 
into a file (before SCIPsolve) using SCIPwriteOrigProblem and the 
transformed sub problem (after SCIPsolve()) using SCIPwriteTransProblem. 
I have obtained the enclosed files subPb.lp and subPbTrans.lp. In the 
transformed sub problem the constraints have disappeared and so the 
solution found by SCIP (in solSubPb.txt) does not respect the original 
constraints (all variables are set to 1).

If I use SCIPreadProb to read the file written by SCIPwriteOrigProblem 
and solve it with SCIPsolve then scip give me the exact result !!

Could you please help me to understand what happens ?

Best regards,

Hélène

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://listserv.zib.de/mailman/private/scip/attachments/20121129/3ced3fb5/attachment.html
-------------- next part --------------
\ SCIP STATISTICS
\   Problem name     : sousPbMin
\   Variables        : 4 (4 binary, 0 integer, 0 implicit integer, 0 continuous)
\   Constraints      : 6
\   Obj. scale       : 1
\   Obj. offset      : 0
Minimize
 Obj: -0.4 y19 -0.2 y20 -0.2 y21 -0.2 y24
Subject to
 cR_0: +9 y19 +4 y20 +10 y21 +4 y24 <= +23
 cR_1: +2 y19 +8 y20 +8 y21 +9 y24 <= +24
 cR_2: +7 y19 +2 y20 +1 y21 +3 y24 <= +21
 cR_3: +3 y19 +7 y20 +3 y21 +8 y24 <= +24
 sum2: +1 y19 +1 y20 +1 y21 +1 y24 >= +2
 C_x0: +1 y19 = +1
Bounds
 0 <= y19 <= 1
 0 <= y20 <= 1
 0 <= y21 <= 1
 0 <= y24 <= 1
Binaries
 y19 y20 y21 y24
End
-------------- next part --------------
\ SCIP STATISTICS
\   Problem name     : t_sousPbMin
\   Variables        : 3 (3 binary, 0 integer, 0 implicit integer, 0 continuous)
\   Constraints      : 0
\   Obj. scale       : 0.2
\   Obj. offset      : -2
Minimize
 Obj: -1 t_y20 -1 t_y21 -1 t_y24
Subject to
Bounds
 0 <= t_y20 <= 1
 0 <= t_y21 <= 1
 0 <= t_y24 <= 1
Binaries
 t_y20 t_y21 t_y24
End
-------------- next part --------------
objective value:                                   -1
y19                                                 1 	(obj:-0.4)
y20                                                 1 	(obj:-0.2)
y21                                                 1 	(obj:-0.2)
y24                                                 1 	(obj:-0.2)