[Rivet] hopefully quick Rivet assertion question

[Caterina Doglioni]

Hi Andy,

sorry for the (not-too) holiday-related delay, I'm back to this now. 
Turns out my previous values were those of the previous event 
(apologies!). So I've picked up a couple more:

phi j1:6.11223
phi j2:2.50349
phi j3:4.45546
python: 
/afs/cern.ch/user/d/doglioni/Work/ThreeJet_Rivet2/local/include/Rivet/Math/MathUtils.hh:419: 
double Rivet::_mapAngleM2PITo2Pi(double): Assertion `rtn >= -TWOPI && 
rtn <= TWOPI' failed.

then on another run:

phi j1:5.4923
phi j2:1.73499
phi j3:3.35263
python: 
/afs/cern.ch/user/d/doglioni/Work/ThreeJet_Rivet2/local/include/Rivet/Math/MathUtils.hh:419: 
double Rivet::_mapAngleM2PITo2Pi(double): Assertion `rtn >= -TWOPI && 
rtn <= TWOPI' failed.
Aborted

None of the two give any problem when plugged into your small .cc code.

I have put the hepmc dump of the events containing the latter one in my 
lxplus public (I can probably find out how to add an event counter if 
that helps...):

~doglioni/hepmc.events

I'll now try to recompile rivet without debug symbols (and cross-check 
the results with your implementation).

Thanks!
Caterina

On 12/10/2013 11:46 AM, Andy Buckley wrote:
> On 09/12/13 13:47, Caterina Doglioni wrote:
>> Hi Andy,
>>
>> I have a possibly strange thing happening to a Rivet code that I'm using
>> (Cigdem in cc) - if it's a bug I'll chase it up through the official
>> channel, but if this is not the case and I'm doing something wrong,
>> emailing just you will spare my silly error being exposed to a wider
>> audience :). Some snippets:
>>
>> leadjets[0] and [1] are 4-momenta that I get from:
>>
>> const Jets jets = applyProjection<JetAlg>(event, "Jets").jetsByPt(100*GeV);
>>
>> out of a Pythia8+Sacrifice jetty final state. However, sometimes (e.g.
>> after 300 events in one of the runs) one of the following lines:
>>
>> delta_phi[j12] = Rivet::deltaPhi(leadjets[0], leadjets[1]);
>> delta_phi[j13] = Rivet::deltaPhi(leadjets[1], leadjets[3]);
>> delta_phi[j23] = Rivet::deltaPhi(leadjets[2], leadjets[3]);
>>
>> crashes my entire code with:
>>
>> python:
>> /afs/cern.ch/user/d/doglioni/Work/ThreeJet_Rivet2/local/include/Rivet/Math/MathUtils.hh:419:
>> double Rivet::_mapAngleM2PITo2Pi(double): Assertion `rtn >= -TWOPI &&
>> rtn <= TWOPI' failed.
>> Aborted (core dumped)
>>
>> I've checked that leadjets[0] and [1] are sane, and that their phi value
>> is from 0 to 2pi, but I haven't managed to track down where things go
>> wrong because this is unfortunately not always happening at the same
>> place! One instance of incriminated jets is here:
>>
>> phi j1:0.387629
>> phi j2:3.61709
>> phi j3:1.82318
>> python:
>> /afs/cern.ch/user/d/doglioni/Work/ThreeJet_Rivet2/local/include/Rivet/Math/MathUtils.hh:419:
>> double Rivet::_mapAngleM2PITo2Pi(double): Assertion `rtn >= -TWOPI &&
>> rtn <= TWOPI' failed.
>>
>> If you can spot the problem without effort from your side I'll be happy
>> to hear it - but let me know if you prefer this to go into official
>> channels.
>
> Hi Caterina, Cigdem... and I've CC'd the Rivet list,
>
> That is very strange. a) I thought that we had already knocked all the
> wrinkles out of those deltaPhi asserts, and b) those phi values are
> already within the -2pi..2pi range and so nothing should happen at all!
> The relevant code is this:
>
> https://rivet.hepforge.org/trac/browser/include/Rivet/Math/MathUtils.hh#L412
>
> and I implemented a tiny test program (attached) to run the same logic
> and assert on the values you supplied (TWOPI = 2*M_PI in
> https://rivet.hepforge.org/trac/browser/include/Rivet/Math/MathHeader.hh#L50).
> Unsurprisingly it's fine:
>
> andy at duality:~/tmp/testfmod$ g++ testfmod.cc -o testfmod
> andy at duality:~/tmp/testfmod$ ./testfmod
> 0.387629 -> 0.387629 = 0.123386*PI
> 3.61709 -> 3.61709 = 1.15136*PI
> 1.82318 -> 1.82318 = 0.580336*PI
>
> Does anyone else know what might be going on here? Do you know which
> specific phi value is causing the trouble, Cate? If you could put the
> analysis code and a HepMC dump of the events (300 events in ASCII is not
> enormous) somewhere ~public, e.g. your AFS public dir then I can look in
> more detail.
>
> A workaround for now is to add CPPFLAGS=-DNDEBUG to your configure or
> make command line before building Rivet (you are using a private build,
> yes?). This will disable the assert. I actually thought that the asserts
> were only active when -g was used, but it turns out that that only
> controls the debug symbols and that assert disabling requires the NDEBUG
> #define, cf.
> http://stackoverflow.com/questions/5354314/how-to-completely-disable-assertion
>
> Cheers,
> Andy
>