Re: [R] svm with GRASS GIS

2012-03-05 Thread giuseppe calamita
Hi Ethienne, we (me and Gab) would like to thank you ! Finally we got what we were looking for but we did it without use the "raster" packagebut we are going to try also with it to see if it allow to have faster computation or data manipulation, If you're interested we can show you the code we

Re: [R] svm with GRASS GIS

2012-02-26 Thread etiennebr
I usually use a rasterLayer object (from raster package) instead of a SpatialGridDataFrame, but you probably just have to bind it to your data : TL_training_2006_id.raw@data$prediction <- pred This will create a band in which you have your predictions. raster package doesn't handle the factors, so

Re: [R] svm with GRASS GIS

2012-02-26 Thread giuseppe calamita
Dear Ethienne, thanks a lot for your help. We finally manage to perform the svm classification in this way: library(spgrass6) ; G <- gmeta6() TL_training_2006_id.raw<-readRAST6("TL_training_2006_id") # classes training area B1_B2_B3_train.raw<-readRAST6(c("AST_L1B_2008_05_2009_area_giusta_1_t

Re: [R] svm with GRASS GIS

2012-02-19 Thread etiennebr
Look at ?predict.svm, you'll see that you need to provide a Matrix, not a data.frame. Etienne -- View this message in context: http://r.789695.n4.nabble.com/svm-with-GRASS-GIS-tp4388006p4403005.html Sent from the R help mailing list archive at Nabble.com. ___

Re: [R] svm with GRASS GIS

2012-02-18 Thread giuseppe calamita
Dear Etienne, I'm a colleauge of Gabriele and I'm more into R (but he is more into GRASS). I'll try to explain you what we didi so far 1) Our ASTER images, (B1, B2 and B3) have 8363134 pixels; we made a subset in order to have training data sets: that is, for each band (B1,B2 and B3) 916 pixels w

Re: [R] svm with GRASS GIS

2012-02-16 Thread Etienne B. Racine
2012/2/15 gab > > Errore in scale(newdata[, object$scaled, drop = FALSE], center = > object$x.scale$"scaled:center", : > (subscript) indice logicol troppo lungo > I'm pretty sure the problem is with your data frame. Maybe if you share the result of dput(training[1:10, ]) # (make sure to include

Re: [R] svm with GRASS GIS

2012-02-15 Thread gab
Ciao Etienne, thank you. Today I tried to understand something more. Here's what I did (The file names are a bit different): *training <- data.frame(cbind(TL_training_2006_id, AST_L1B_2008_05_2009_area_giusta_1, AST_L1B_2008_05_2009_area_giusta_2, AST_L1B_2008_05_2009_area_giusta_3N))* Then ... *x

Re: [R] svm with GRASS GIS

2012-02-15 Thread Etienne B. Racine
Gab, Make sure you have variables for each training. training <- data.frame(Training_2006, AST_L1B_1, AST_L1B_2, AST_L1B_3N) If you can't do that, then you don't have as many training observations than you have predictive informations. Make sure to create a line for each set of predictive pixels

[R] svm with GRASS GIS

2012-02-14 Thread gab
Dear R Community- I am a new user of R. I am using R with GRASS GIS. I would apply svm "on" raster data in GRASS. Basically I have a raster with "areas training" and other three raster (each represents a band of ASTER satellite image). My goal is to classify, according to training areas, the 3 ra