On 08/25/2011 10:54 AM, Tom Vanwalleghem wrote: > Dear R helpers, > I'm new to R and struggling with applying functions to a spatial grid data > frame, called data for example.data has a variable named "slope" and "uparea" > Basically, I need to calculate the tan(data$slope)Next, I need to divide > data$uparea by data$slope and take the log() of that all > In the basic examples I found how to make simple multiplications with a > scalar likedata[["slope"]] = data[["slope"]]/2 # assigns new attribute > I come from a background in GIS and fortran, so used to dealing with ordinary > matrices, I'll admit I'm having trouble with understanding the format of this > spatial grid data frame structureI've been trying different methods to index > the data frame, or working with the function "lapply" but so far I can't seem > to get my head wrapped around it. > I appreciate any help.TomResearcher@University of CordobaSpain > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. I would most surely take a look at the raster package, this might also be more intuitive for you. In addition, there is a special mailing list for spatial tasks, r-sig-geo. These kinds of questions are more suitable for that mailing list.
cheers, Paul -- Paul Hiemstra, Ph.D. Global Climate Division Royal Netherlands Meteorological Institute (KNMI) Wilhelminalaan 10 | 3732 GK | De Bilt | Kamer B 3.39 P.O. Box 201 | 3730 AE | De Bilt tel: +31 30 2206 494 http://intamap.geo.uu.nl/~paul http://nl.linkedin.com/pub/paul-hiemstra/20/30b/770 ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
