Hello, I'm really new using Monteverdi, but I need to use ir for the final project in my studies. I want to do the SVM Classification with SHP files from Q-GIS, but I don't know how to do it in windows and I don't know how to program, I was using it in Ubuntu but is very different in Windows, I hope you can give an idea.
Thanks! Relder El martes, 28 de enero de 2014 15:17:46 UTC+1, Charles Peyrega escribió: > > Hi Saygin. > > Let us consider your smallest class, the size of which will limit the > maximal number of training/validation pixels. You can write: > > Nb_Pixels_Smallest_Class = 115 pixels > Ratio = 0.5 > > Then, for EACH class, your training is made over about (0.5 x 115) = 57.5 > pixels. Moreover, you have 4 classes, then you will train your model over a > total number of (4 x 57.5) = 230 pixels, which approximately corresponds to > your > actual number of 232 training samples. Your validation data set is > composed of 184 pixels corresponding to about (184./4) = 46 pixels for EACH > class, which is quite close of the 57.5 pixels value of the training set. > In fact both values are not strictly identical because the actual number of > pixels over which the random sample selection is made (115 pixels) is too > small to obtain similar values. However, you can consider that they are > close enough to each other. > > Please find below another example I gave as an answer over the otb-users > mailing list concerning a similar issue but concerning both "sample.mt" > and "sample.mv" parameters of the OTB Application > otbapp_TrainImagesClassifier, which also have an infmuence of the actual > number of samples randomly selected: > > Considering Nb_Pixels_Smallest_Class = 430 pixels. Let us consider now an > unbalanced ratio R = 0.1, (90% is used for Training and 10% for > Validation). You will randomly select about 387 samples for T and 43 for V > in EACH of your nbC classes if "sample.mt" = "sample.mv" = (-1). > > If Ratio=0.1: (90% is used for T and 10% for V): > > If "sample.mt" = 100 < 430*0.9, you will use about 100 samples for T for > each of your nbC classes. > If "sample.mv" = 100 > 430*0.1, you will use about 43 samples for V for > each of your nbC classes. > > Then, to sum up, if you want to use the maximal available number of > samples per class for T and V, you simply need to choose "sample.mt" = " > sample.mv" = (-1). However, this maximal number of samples per class will > be limited by the size of your smallest class. Then, you can set the > ratio R according to your needs. > > > Best regards. > > Charles Peyrega > > > > Le 28/01/2014 12:43, saygin a écrit : > > > Hello, > > I am trying to train my .tif image with approximately 1500 pixels. I > have 4 classes and one of them has the lowest training with 115 pixels. If > I chose training and validation sample ratio 0.5, and using SVM OpenCV RBF > with parameter optimization I get 232 training and 184 validation at log > file. I am not very familiar with OTB and want to ask does not it > use approximately half of all training pixels? > > Thanks > -- > -- > 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 [email protected]<javascript:> > To unsubscribe from this group, send email to > [email protected] <javascript:> > 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 [email protected] <javascript:>. > For more options, visit https://groups.google.com/groups/opt_out. > > > > -- > <http://www.c-s.fr> *Charles PEYREGA*, *PhD* > Ingénieur d'études métier > *Business Unit E-SPACE & Geo > Information*<https://thor.si.c-s.fr/blogs/cs-blogs-business/>* > - Département APPLICATIONS* > > *CS Systèmes d'Information* > Parc de la Grande Plaine - 5, Rue Brindejonc des Moulinais - BP 15872 > 31506 Toulouse Cedex 05 - FRANCE > +33 561 17 65 14 - [email protected] <javascript:> > -- -- 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 [email protected] To unsubscribe from this group, send email to [email protected] 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 [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
