FYI I've opened an issue to generate the reference documentation of applications with Shark and document these options:
https://bugs.orfeo-toolbox.org/view.php?id=1400 2017-05-12 10:06 GMT+02:00 Jordi Inglada <jordi.ingl...@cesbio.eu>: > Hi Nafissa, > > You can build OTB with Shark. If you use the superbuild, you can > activate the cmake configuration > > OTB_USE_SHARK:BOOL=ON > > which will build Shark as an OTB dependency and then build OTB to use > Shark. > > Make sure that OTB is also compiled with > > OTB_USE_SHARK:BOOL=ON > > If you just reconfigure the superbuild after building without Shark, I > think Shark is built, but OTB is not rebuilt to use Shark. > > Once everything is OK, you should find that for instance in > otbcli_TrainVectorClassifier the -classifier options allows to choose > between "rf" and "sharkrf". The first one is OpenCV's. > > Now, just some feedback. Shark is supposed to be faster in the learning > step because the trees are learned in parallel (by the way, make sure > that OpenMP is used for both Shark and OTB, check the CMakeCache.txt > files in the build directories). Actually, in some cases, Shark can be > way slower than OpenCV. There are several reasons for that. There are > some inefficiencies in Shark when the number of features is very high (a > solution is in progress, see > https://github.com/Shark-ML/Shark/issues/179 for details). Also, Shark > builds full trees, while OpenCV stops at a chosen depth (25 by default). > > Good luck. > > Jordi > > On Thu 11-May-2017 at 15:09:38 +0200, Nafissa Sfaksi <nsfa...@gmail.com> > wrote: > > Hello, > > > > I'am trying to improve my process chain for Sentinel 2 with OTB, and as > you said few weeks before, there're two implementations of the Random > Forest in OTB; > > My question is about how can I choose between opencv and shark libs? and > if it's possible to force the process to use shark instead of opencv? > > > > Best regards > > > > Le mardi 28 mars 2017 15:31:11 UTC+2, Manuel Grizonnet a écrit : > > > > Hi, > > > > note first there are 2 implementations of random forests now available > in OTB since release 5.8. One from openCV and the other one from the shark > machine learning library (which allows parallel training). Both > implementations are wrappers around those libraries and you generally > > have to dig into libraries documentation to find out such information. > > > > Regarding the criteria, I think that both opencv and shark > implementations use the Gini criterion (for shark I'm quite sure). Would be > glad if someone who know a bit more those implementations can confirm this. > > > > Note also that I don't think that we have a way in otb to change this > criteria with shark implementation even if there is a way to do this in > shark base class. Perhaps something that could be added to the > SharkMachineLearningModel in the future. > > > > Regards, > > > > 2017-03-27 9:46 GMT+02:00 Nafissa Sfaksi <nsf...@gmail.com>: > > > > Hi, > > With the tool TrainClassifier we can put several parameters but is it > possible to see which criteria is used for the method? > > I mean the tool use Gini criterion or entropy criterion? > > Thanks for reply > > Nafissa > > > > -- > > -- > > Check the OTB FAQ at > > http://www.orfeo-toolbox.org/FAQ.html > > > > You received this message because you are subscribed to the Google > > Groups "otb-users" group. > > To post to this group, send email to otb-...@googlegroups.com > > To unsubscribe from this group, send email to > > otb-users+...@googlegroups.com > > For more options, visit this group at > > http://groups.google.com/group/otb-users?hl=en > > --- > > You received this message because you are subscribed to the Google > Groups "otb-users" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to otb-users+...@googlegroups.com. > > For more options, visit https://groups.google.com/d/optout. > > > > -- > > Manuel Grizonnet > > > > -- > > -- > -- > Check the OTB FAQ at > http://www.orfeo-toolbox.org/FAQ.html > > You received this message because you are subscribed to the Google > Groups "otb-users" group. > To post to this group, send email to otb-users@googlegroups.com > To unsubscribe from this group, send email to > otb-users+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/otb-users?hl=en > --- > You received this message because you are subscribed to the Google Groups > "otb-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to otb-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Manuel Grizonnet -- -- Check the OTB FAQ at http://www.orfeo-toolbox.org/FAQ.html You received this message because you are subscribed to the Google Groups "otb-users" group. To post to this group, send email to otb-users@googlegroups.com To unsubscribe from this group, send email to otb-users+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/otb-users?hl=en --- You received this message because you are subscribed to the Google Groups "otb-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to otb-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
