annual means, sums

[Jörg Kaduk <joerg@xxxxxxxxxxxxxxxxxxx>]

Hi,
I bet a trivial question -
I have monthly data, say 360 months. I want to make annual data
out of those and it seems that something like:

xxx[i=3,GL=1:360:12@ave] or xxx[i=3,GL=1:360:12@sum] 

works fine. A question about a detail:
The average runs over months 1-12, 13-24, 25-36 ... ? Or
should I use 
xxx[i=3,GT=0.5:360.5:12@ave] or xxx[i=3,GT=0.5:360.5:12@sum] 

to be on the save side?

Now, my real question is:
I get the mean plotted on the 13'th month. Is there a way
to talk ferret into plotting the means in the middle of the 
years? I.e. at the end of the months 6, 18, ...?

Thanks for your time and thoughts,
Cheers,
Joerg



--
Jörg Kaduk                              Tel.: 1 650 325 1521 x 416
Carnegie Institution of Washington      FAX: 1 650 325 6857
Dept. of Plant Biology
260 Panama Street                       joerg@jasper.stanford.edu
Stanford, CA 94305-1297                
http://Jasper.Stanford.EDU/joerg/