well, it "kind of works" now, I get means from the 61st SST-value on (which is reasonable, so no "carful discarding" of the first 60 values) but aswell I only get means until the 186st SST-value (although I 've got about 4900 in total). Allt the rest is "NA" - besides the 60th value is "NaN" Any idea, why it runs the loop only roughly 2 times then?
thanks, birte lauramorg...@bluewin.ch wrote: > > Sorry, I meant: > > If, suppose, the name of your dataframe is "dataframe" , you could try > something like: > mean60days<-c() > for(i in 1:length(dataframe$SST)) > + { > + mean60days[[i]]<-mean(dataframe$SST[i-60:i]) > + } > I'm not really sure it will work... my skills aren't that great... > Anyway, it worked on a sample I tried it on, but you have to be careful > and discard the first 60 values!! > Hope it works, > ciao > Laura > > > > > Dear RUsers, > I guess this is an easy question for someone a little familiar with > programming...(which I am not)... > > I've got 2 colummns, one shows just dates(SST_date, Class 'Date' num), the > other one shows the SeaSurfaceTemperature (SST, num) at that certain date. > > SST_date SST > 2008-01-01 22.2 > 2008-01-02 21.8 > 2008-01-03 22.8 > 2008-01-04 22.9 > 2008-01-05 23.1 > 2008-01-06 23.2 > ... > ... > > now, I would like to add a column that shows the mean SST over the last > (e.g.) 60 days (for that specific date). > > My biological question is, whether the birthweight of an animal at a > specific birthdate changes due to the SST over the last 60 days before > birth. (SST is an indicator for food abundance - if food is scarce, > mothers > can't feed much and hence, pups are born lighter!?) > Up to now, I can only show, whether the SeaSurfaceTemperatures on the > birthdate can have an influence on birthweight, which is not what I want > to > do... > > Can anybody tell me, how to start, where to look it up or help me even > more? > thanks in advance. > Birte > > -- > View this message in context: > http://www.nabble.com/mean-over-previous-cells-tp22116807p22116807.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org 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. > > ______________________________________________ > R-help@r-project.org 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. > > -- View this message in context: http://www.nabble.com/mean-over-previous-cells-tp22116807p22118880.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org 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.