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Crash with GAMS v28.1 (x64)

Posted: Thu Aug 15, 2019 7:47 pm
by ALe
The tiny GAMS program below (meaningless as such, only purpose is to reproduce the problem) causes a fully reproducible crash in GAMS v28.1 (discovered by a colleague, while trying my GAMS code). However, all earlier versions seem to work well with it, as I think should be the case. Can anyone explain why the new version crashes? Hopefully the earlier well-working status will be restored for such GAMS constructs.
crash-example.gms
Crash Example
(959 Bytes) Downloaded 23 times
*---------------------------------------------------------------------------------------
$offlisting
$onempty

SETS
s hours /H01*H24/
lim /lo,up,fx,n/
bd(lim) bound /lo,up,fx/
bdneq(lim) /lo,up/
;

ALIAS (s, ts, sl);

PARAMETERS
win_time time window //
hours(s) timeslice hour //
cost_puts(s) cost of putsing //
winscost cost on winsing /1/
;

cost_puts(s)=4;
hours(s)=ord(s)-0.5;
win_time=4;

POSITIVE VARIABLES
var_puts(s) putty
var_wins(s,bd) winsing
;

FREE VARIABLES
Objz objective variable
;

EQUATIONS
eq_obj objective function
eq_win winning
;

eq_obj.. Objz =e= sum(s, cost_puts(s)*var_puts(s)+winscost*sum(bdneq(bd),var_wins(s,bd)));

eq_win(s)..

sum(bd,var_wins(s,bd)) =e=
sum(ts(sl--1)$(mod(hours(s)-hours(sl)+0.5+24,24)<win_time),var_puts(sl)+var_wins(sl,'up')-var_wins(ts,'up'));

model test/
eq_obj
eq_win
/;

solve test min objz using lp;
*---------------------------------------------------------------------------------------
Thank you.

Re: Crash with GAMS v28.1 (x64)

Posted: Fri Aug 16, 2019 8:29 am
by bussieck
This is pretty embarrassing. Thanks for taking the time to make a small and reproducible example. The crash is likely to be related to some speed improvements in the model generation. We will look into this and fix this ASAP.

-Michael

Re: Crash with GAMS v28.1 (x64)

Posted: Wed Aug 21, 2019 11:20 am
by bussieck
This has been fixed in GAMS 28.2.0.

-Michael