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<div class="moz-cite-prefix">Dear SCIP community,<br>
<br>
I thank you for your response, but there was the following bug in
my program:<br>
<br>
In order to solve the quadratic travelling salesman problem, I
defined a linearizatin similar to the (normal) travelling salesman
problem first, relaxed all subtour inequalities and solved the
remaining quadratic 2-matching problem. Then I called
“SCIPfreeTransform(sCIP);”, added some subtour constraints and
solved the enlarged ILP again. The problem was that I set a lower
bound before starting the new solving process. But I have to set a
upper bound in maximization problems. Clearly, this problem does
not occur by adapting the objective function, but does occur by
changing the optimization sense.<br>
<br>
Thank you again and excuse this mistake of me.<br>
<br>
Yours sincerely,<br>
Rostislav Stanek<br>
<br>
<br>
<br>
Dne 14.2.2015 v 17:07 dinesh kumar napsal(a):<br>
</div>
<blockquote
cite="mid:CALpU0rp-GZg+p-=+6SmAxoX0YOdtMQMNL_h-UAaXBFgBB01xHg@mail.gmail.com"
type="cite">
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<div dir="ltr">Dear,
<div>we would love to help you but we need to see the problem
objective as well as your code for more information.</div>
<div><br>
</div>
<div>Thank you </div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On 13 February 2015 at 06:32, Rostislav
Stanek <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:rostislav.stanek@uni-graz.at" target="_blank">rostislav.stanek@uni-graz.at</a>></span>
wrote:<br>
<blockquote class="gmail_quote">Dear SCIP community,<br>
<br>
I have the following problem:<br>
<br>
By solving a minimization problem described as an ILP
everything is working fine. Then I changed the signs by all
objective function coefficients in order to obtain the
corresponding maximization problem and everything is working
fine as well. But by using the option<br>
<br>
SCIPsetObjsense(sCIP, SCIP_OBJSENSE_MAXIMIZE);<br>
<br>
an error occurs:<br>
<br>
src/lpi/lpi_cpx.c:3900: SCIPlpiGetNorms: Assertion
`lpi->messagehdlr != ((void *)0)' failed.<br>
<br>
Program received signal SIGABRT, Aborted.<br>
0x00007ffff694f0d5 in __GI_raise (sig=<optimized out>)
at ../nptl/sysdeps/unix/sysv/linux/raise.c:64<br>
64 ../nptl/sysdeps/unix/sysv/linux/raise.c: Adresář nebo
soubor neexistuje.<br>
(gdb) bt<br>
#0 0x00007ffff694f0d5 in __GI_raise (sig=<optimized
out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64<br>
#1 0x00007ffff695283b in __GI_abort () at abort.c:91<br>
#2 0x00007ffff6947d9e in __assert_fail_base
(fmt=<optimized out>, assertion=0x1711318
"lpi->messagehdlr != ((void *)0)",<br>
file=0x17104d8 "src/lpi/lpi_cpx.c", line=<optimized
out>, function=<optimized out>) at assert.c:94<br>
#3 0x00007ffff6947e42 in __GI___assert_fail
(assertion=0x1711318 "lpi->messagehdlr != ((void *)0)",
file=0x17104d8 "src/lpi/lpi_cpx.c", line=3900,<br>
function=0x17116a0 "SCIPlpiGetNorms") at assert.c:103<br>
#4 0x0000000000ab6b73 in SCIPlpiGetNorms (lpi=0x22ccfd0,
blkmem=0x20a4640, lpinorms=0x22da8a8) at
src/lpi/lpi_cpx.c:3900<br>
#5 0x000000000054a087 in SCIPlpGetNorms (lp=0x22bf8b0,
blkmem=0x20a4640, lpinorms=0x22da8a8) at src/scip/lp.c:12228<br>
#6 0x00000000006c18d9 in SCIPtreeStartProbing
(tree=0x22da830, blkmem=0x20a4640, set=0x20a6660,
lp=0x22bf8b0, strongbranching=0)<br>
at src/scip/tree.c:5954<br>
#7 0x0000000000656258 in SCIPstartProbing (scip=0x209d360)
at src/scip/scip.c:29494<br>
#8 0x0000000000911c84 in performRandRounding
(scip=0x209d360, heurdata=0x2201490, sol=0x2327910,
cands=0x2b4dea0, ncands=62, propagate=1,<br>
result=0x7fffffffc818) at src/scip/heur_randrounding.c:94<br>
#9 0x0000000000912707 in performLPRandRounding
(scip=0x209d360, heurdata=0x2201490, heurtiming=2,
propagate=1, result=0x7fffffffc818)<br>
at src/scip/heur_randrounding.c:320<br>
#10 0x0000000000912d9c in heurExecRandrounding
(scip=0x209d360, heur=0x2201520, heurtiming=2,
nodeinfeasible=0, result=0x7fffffffc818)<br>
at src/scip/heur_randrounding.c:458<br>
#11 0x000000000051060a in SCIPheurExec (heur=0x2201520,
set=0x20a6660, primal=0x22da7a0, depth=0,
lpstateforkdepth=-1, heurtiming=2,<br>
nodeinfeasible=0, ndelayedheurs=0x7fffffffc81c,
result=0x7fffffffc818) at src/scip/heur.c:454<br>
#12 0x0000000000699d8d in SCIPprimalHeuristics
(set=0x20a6660, stat=0x209d450, prob=0x22db820,
primal=0x22da7a0, tree=0x22da830, lp=0x22bf8b0,<br>
nextnode=0x0, heurtiming=2, nodeinfeasible=0,
foundsol=0x7fffffffc9b0) at src/scip/solve.c:313<br>
#13 0x00000000006a0c82 in priceAndCutLoop (blkmem=0x20a4640,
set=0x20a6660, messagehdlr=0x0, stat=0x209d450,
transprob=0x22db820,<br>
origprob=0x209e020, primal=0x22da7a0, tree=0x22da830,
lp=0x22bf8b0, pricestore=0x2301e70, sepastore=0x2389280,
cutpool=0x231f270,<br>
delayedcutpool=0x2302030, branchcand=0x22c1e10,
conflict=0x22daa20, eventfilter=0x22b6040,
eventqueue=0x225a3c0, initiallpsolved=0,<br>
cutoff=0x7fffffffd02c, unbounded=0x7fffffffd030,
lperror=0x7fffffffce54, pricingaborted=0x7fffffffce50) at
src/scip/solve.c:2271<br>
#14 0x00000000006a3013 in solveNodeLP (blkmem=0x20a4640,
set=0x20a6660, messagehdlr=0x0, stat=0x209d450,
origprob=0x209e020, transprob=0x22db820,<br>
primal=0x22da7a0, tree=0x22da830, lp=0x22bf8b0,
pricestore=0x2301e70, sepastore=0x2389280,
cutpool=0x231f270, delayedcutpool=0x2302030,<br>
branchcand=0x22c1e10, conflict=0x22daa20,
eventfilter=0x22b6040, eventqueue=0x225a3c0,
initiallpsolved=0, newinitconss=0, cutoff=0x7fffffffd02c,<br>
unbounded=0x7fffffffd030, lperror=0x7fffffffce54,
pricingaborted=0x7fffffffce50) at src/scip/solve.c:2788<br>
#15 0x00000000006a5513 in propAndSolve (blkmem=0x20a4640,
set=0x20a6660, messagehdlr=0x0, stat=0x209d450,
origprob=0x209e020, transprob=0x22db820,<br>
primal=0x22da7a0, tree=0x22da830, lp=0x22bf8b0,
relaxation=0x22d9110, pricestore=0x2301e70,
sepastore=0x2389280, branchcand=0x22c1e10,<br>
cutpool=0x231f270, delayedcutpool=0x2302030,
conflict=0x22daa20, eventfilter=0x22b6040,
eventqueue=0x225a3c0, focusnode=0x2306ff0, actdepth=0,<br>
timingmask=1, propagate=1, solvelp=1, solverelax=1,
forcedlpsolve=0, nlperrors=0x7fffffffce30, fullpropagation=0x7fffffffce48,<br>
propagateagain=0x7fffffffce44, initiallpsolved=0x7fffffffce38,
solvelpagain=0x7fffffffce40, solverelaxagain=0x7fffffffce3c,<br>
cutoff=0x7fffffffd02c, unbounded=0x7fffffffd030,
lperror=0x7fffffffce54, pricingaborted=0x7fffffffce50,
forcedenforcement=0x7fffffffce58)<br>
at src/scip/solve.c:3442<br>
<br>
Can you help me / explain it?<br>
<br>
Thank you for your response in advance.<br>
<br>
Yours sincerely,<br>
Rostislav Stanek<br>
<br>
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