Thank Gavin, I will send the message in R-SIG-Geo. Momadou ________________________________ De : Gavin Simpson <[email protected]>
Cc : "[email protected]" <[email protected]> Envoyé le : Lundi 28 Novembre 2011 17h58 Objet : Re: [R-sig-eco] Problem with a loop Hi Momadou, This is *not* a general help list for R. It is a SIG for ecological and environment-related questions. Your question would be suitable for the R-SIG-Geo list or the general R-Help mailing list, but not here. Gavin On Mon, 2011-11-28 at 15:35 +0000, momadou sow wrote: > Hi, > I have a correct > code to extract pixel value of my image and to stock the result in a folder. > See > correct code in attached file. But as I have several images, I would like to > do a loop to > extract all pixel values at the same time and stock all the results in > different matrices (Mat1, Mat2, Mat3, etc.) in the same folder. > I try this > code but it is not correct. > >library(raster) > >a <- NULL > >for(i in 2002273:2002361){ > >a<-(adresse("C:\\Users\\Momadou\\Desktop\\Subset\\Subset_Site1_NDII\\NDII_Subset_2002\\Sahel_Site1_",i,sep="")) > > > >RasterToColonne <- function(AdresseRaster){ # to transform raster to Colum > >a <- raster(adresse) > >CentreRaster <- rasterToPoints(a) > >PixelColonne <- as.data.frame(CentreRaster) > >PixelColonne <- cbind(PixelColonne,coordonnee = > >paste(PixelColonne[,1],PixelColonne[,2],sep=" ")) > >colnames(PixelColonne) <- > >c("Longitude","Latitude","ValeurPixel","Coordonnees") > >return(PixelColonne) > >} > >Mat[i]<- RasterToColonne(adresse) > >write.table(Mat[i], "C:\\Users\\Momadou\\Desktop\\Mat[i].txt",sep=" ") > Can you > help me to solve this problem? > Thank in > advance > Mamadou > _______________________________________________ R-sig-ecology mailing list > [email protected] > https://stat.ethz.ch/mailman/listinfo/r-sig-ecology -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Dr. Gavin Simpson [t] +44 (0)20 7679 0522 ECRC, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/ UK. WC1E 6BT. [w] http://www.freshwaters.org.uk %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% [[alternative HTML version deleted]]
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