Philip, this sounds like an interesting approach. Do you do anything in particular to handle larger datasets? How large are your images?
Robert Denham Environmental Statistician Remote Sensing Centre Telephone 07 3896 9899 www.nrw.qld.gov.au Department of Natural Resources & Water QScape Building, 80 Meiers Road, Indooroopilly Qld 4068 ---------------------------------------------------------------------- Message: 1 Date: Sun, 15 Jul 2007 07:40:12 -0600 From: Philip Riggs <[EMAIL PROTECTED]> Subject: [R-sig-Geo] map algebra with ascii grid To: r-sig-geo@stat.math.ethz.ch Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed >> Dear R Users, >> >> could you please advise me on doing map algebra with spatial grids? >> It's the first time I am using spatial objects in R. I have imported >> an ascii grid file and wanted to round the values in it or sum with a >> value, but it gives an error message: >> >I use Python with Numpy/GDAL python bindings all the time to do spatial algebra and manipulate grids. >It has all the math functions, and in the case of categorical data you can reassign values. Then I >use rpy to do any statistical analyses in R. You could also do your manipulation in Python, then >save the grid in an appropriate format for import into R to do the statistical analyses. > Philip ************************************************************************ The information in this email together with any attachments is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any form of review, disclosure, modification, distribution and/or publication of this email message is prohibited, unless as a necessary part of Departmental business. If you have received this message in error, you are asked to inform the sender as quickly as possible and delete this message and any copies of this message from your computer and/or your computer system network. _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo