The gsummary function was intended to apply a summary function to each column in each of the groups of observations. The (implicit) definition of a summary function is that it produces a scalar from a vector. (See the groupings of functions in Table A.1, p. 472 of "Statistical Models in S", a.k.a. "The White Book".)
I don't think you need to use gsummary for your application. You may be able to use tapply or a combination of split and lapply instead. On 8/3/06, Mike Saunders <[EMAIL PROTECTED]> wrote: > Could someone give me a hand with the format of the gsummary function? > Basically, I have a large set of xyz coordinates generated by LiDAR data (>37 > million points) and I am trying to derive various summary statistics on the > z-coordinates by a grid cell. I wrote a function to do this by creating > factors from the x- and y- coordinates and then using gsummary. However, I > want the function to calculate BOTH the max z-value in a grid cell and the > number of z-values in that cell. gsummary is supposed to be able to use a > list a functions as input to FUN, but I am having trouble coding it > correctly. Here is what I came up to so far. > > gr<-gsummary(xyz.packet,FUN=list(numeric=max,numeric=length),omitGroupingFactor=T,form=~X/Y) > > The help for the function gives no examples using multiple functions as a FUN > value, so the help pages haven't been overly useful in this case. > > Thanks in advance, > Mike > > Mike R. Saunders > Forest Biometrician > Cooperative Forest Research Unit > University of Maine > 5755 Nutting Hall > Orono, ME 04469-5755 > > 207-581-2763 (O) > 207-581-2833 (F) > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] 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. > ______________________________________________ [email protected] 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.
