Dear Johannes, Looks like you are in the field of error propagation [http://spatial-accuracy.org/workshopSUP].
Both mean and median are valid statistical parameters to describe the central tendencies. What is often more interesting is the propagated uncertainty in the final estimates. I assume that your output is a binomial variable? In our HESS paper [http://www.hydrol-earth-syst-sci-discuss.net/7/767/2010/hessd-7-767-2010.html], we use the Information entropy index to quantify the uncertainty of the model (we deal with a binary/Bernoulli variable). The code and the dataset can be obtained from: [http://geomorphometry.org/content/uncertainty-stream-networks-derived-elevation-data] A number of (Gaussian) grid statistics parameters can be derived using SAGA GIS: > library(RSAGA) > rsaga.get.usage(lib="geostatistics_grid", module=5) SAGA CMD 2.0.3 library path: C:/PROGRA~1/R/R-210~1.1/library/RSAGA/saga_vc/modules library name: geostatistics_grid module name : Statistics for Grids Usage: 5 -GRIDS <str> [-MEAN <str>] [-MIN <str>] [-MAX <str>] [-VAR <str>] [-STDDEV <str>] [-STDDEVLO <str>] [-STDDEVHI <str>] -GRIDS:<str> Grids Grid list (input) -MEAN:<str> Arithmetic Mean Grid (optional output) -MIN:<str> Minimum Grid (optional output) -MAX:<str> Maximum Grid (optional output) -VAR:<str> Variance Grid (optional output) -STDDEV:<str> Standard Deviation Grid (optional output) -STDDEVLO:<str> Mean less Standard Deviation Grid (optional output) -STDDEVHI:<str> Mean plus Standard Deviation HTH, T. Hengl > -----Original Message----- > From: r-sig-geo-boun...@stat.math.ethz.ch [mailto:r-sig-geo- > boun...@stat.math.ethz.ch] On Behalf Of Johannes Signer > Sent: Sunday, May 02, 2010 5:30 PM > To: r-sig-geo@stat.math.ethz.ch > Subject: [R-sig-Geo] Summary of multiple rasters > > Dear List, > > my problem is as follows: > > I have a model that predicts me the distribution of a species in the > landscape. I run that model several times and now I am not sure which > summary statistic to use (mean, median). Is there an index to get an idea of > how the prediction in each cell are distributed? > > Any are greatly appreciated, > > Thanks > Johannes > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo