Thanks Roman and Robert! I'll try! Milena
2012/10/10 Robert J. Hijmans <[email protected]> > Perhaps something like this? > > library(raster) > file_path <- paste(folder_path, file_list, sep = "") > s <- stack(file_path) > cappi_raster_sum <- sum(s, na.rm=TRUE) * ratio > > > Robert > > > On Wed, Oct 10, 2012 at 7:47 AM, Roman Luštrik > <[email protected]>wrote: > >> Your example or description is not perfectly clear to me so I may be off, >> but wouldn't you be better off by reading your files into a RasterBrick or >> RasterStack, summing through the layers and multiplying by a ratio? >> >> Cheers, >> Roman >> >> >> >> On Wed, Oct 10, 2012 at 4:29 PM, Milena <[email protected]> wrote: >> >> > Hello! >> > I hope someone can help me! I have radar images, they're matrixes >> 240x240 >> > in TXT format. The information is about rain, in mm/h. I need to >> transform >> > them to total rain (only mm), so I have to multiply the matrixes to 5/60 >> > (temporal resolution is 5 minutes). >> > Well, I have a script that theorically can make this ratio. It makes a >> > looping too because I have too many images. But, it's not working... >> > Any ideia about what is going wrong? Or another way to make this >> > multiplication? >> > Thanks!!!! >> > Milena Fogliarini Brolesi >> > (Unicamp) >> > >> > #create the raster based in another raster image (cappi_dimension)and >> set >> > value = 0 to make the sum possible >> > >> > >> cappi_example<-raster(readAsciiGrid("C:/Users/MFB/Documents/Mestrado/cappi_teste/V1_CAPPIH030R2_20030101_1534.txt", >> > as.image = FALSE, proj4string = CRS("+proj=longlat +datum=WGS84"))) >> > cappi_example[is.na(cappi_example)]<-0 >> > cappi_raster_sum<-setValues(raster(cappi_example, filename = >> > "cappi_raster_sum", values = NULL), values = 0) >> > >> > #for loop to read all images in a folder, sum all images and aply a >> ratio >> > to transform mm/h in mm >> > ratio<-5/60 >> > >> > for (ii in 1: length(file_list)) { >> > >> > file_path<-paste(folder_path, file_list [ii],sep = "") >> > library(raster) >> > cappi<-raster(readAsciiGrid(file_path, as.image = FALSE, proj4string = >> > CRS("+proj=longlat +datum=WGS84"))) >> > cappi[is.na(cappi)]<-0 >> > cappi_raster_sum<-sum(cappi_raster_sum,cappi)*ratio >> > } >> > summary(cappi_raster_sum) >> > >> > [[alternative HTML version deleted]] >> > >> > _______________________________________________ >> > R-sig-Geo mailing list >> > [email protected] >> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo >> > >> >> >> >> -- >> In God we trust, all others bring data. >> >> [[alternative HTML version deleted]] >> >> _______________________________________________ >> R-sig-Geo mailing list >> [email protected] >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >> > > [[alternative HTML version deleted]]
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