Alex, On Thursday 04 December 2008 05:48:59 pm [EMAIL PROTECTED] wrote: > > I am wondering if anyone has alternative options (preferably with > > example) that enable to read in large grids, do some calculations and > > save a new grid?
You may need a hammer, and R is the screwdriver. But it's a useful screwdriver, so maybe you can make it work here. AsciiGrid files are very simple. They are text obviously, with a 5 or 6 line header and then rows of grid cell values. This means that fairly generic R I/O commands can work with them. scan() is where I'd start if I were you. Actually I'd start with another thing Barry brought up - make yourself a really small asciigrid file, like 4x3, and practice on that while you figure out your processing. Here's one I have used: modify the values as you see fit. nrows 4 ncols 5 xllcorner 0.000000 yllcorner 0.000000 cellsize 10.000000 NODATA_value -9999 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 yours, Ashton -- Ashton Shortridge Associate Professor [EMAIL PROTECTED] Dept of Geography http://www.msu.edu/~ashton 235 Geography Building ph (517) 432-3561 Michigan State University fx (517) 432-1671 _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
