Many thanks everybody for your kind help. John​
On Mon, Apr 6, 2015 at 12:11 AM, David Winsemius <dwinsem...@comcast.net> wrote: > > On Apr 5, 2015, at 2:40 PM, John Wasige wrote: > > > Thanks Jim! > > > > Do you have an idea on how I can go about getting bi-monthly (twice a > > month) results for the month with 28, 29, 30 and 31 daily observations? > > > > Thanks for your help > > raindate <- seq.Date(as.Date("1982-01-01"), as.Date("1983-01-01"),by=1) > > paste( format( head(raindate,30), "%Y"), > cut(as.numeric(format( head(raindate,30),"%d")), c(0,16,32) ), > sep="_") > > [1] "1982_(0,16]" "1982_(0,16]" "1982_(0,16]" "1982_(0,16]" > [5] "1982_(0,16]" "1982_(0,16]" "1982_(0,16]" "1982_(0,16]" > [9] "1982_(0,16]" "1982_(0,16]" "1982_(0,16]" "1982_(0,16]" > [13] "1982_(0,16]" "1982_(0,16]" "1982_(0,16]" "1982_(0,16]" > [17] "1982_(16,32]" "1982_(16,32]" "1982_(16,32]" "1982_(16,32]" > [21] "1982_(16,32]" "1982_(16,32]" "1982_(16,32]" "1982_(16,32]" > [25] "1982_(16,32]" "1982_(16,32]" "1982_(16,32]" "1982_(16,32]" > [29] "1982_(16,32]" "1982_(16,32]" > > Another method would be to use `cut` on as.POSIXlt(raindate)$mday > > -- > David. > > > > John. > > > > On Sun, Apr 5, 2015 at 11:25 PM, Jim Lemon <drjimle...@gmail.com> wrote: > > > >> Hi John, > >> One way is to create an index variable that will divide your data into > the > >> appropriate intervals. There are a number of ways to do this. Say you > want > >> the "two month" version of bimonthly and you have a date variable > >> ("raindate") for each observation like "1982-01-01". > >> > >> date_order<-paste(rep(month.abb,30),rep(1982:2011,each=12),sep="") > >> > >> > month_index<-factor(format(as.Date(raindate,"%Y-%m-%d"),"%b%Y"),levels=date_order) > >> > >> You can then subset the raster matrices by "month_index" and average > them > >> for each group > >> > >> Jim > >> > >> On Mon, Apr 6, 2015 at 3:08 AM, Jeff Newmiller < > jdnew...@dcn.davis.ca.us> > >> wrote: > >> > >>> Please stop posting using HTML (as the Posting Guide warns you), and > >>> follow John Kane's advice. Your reply below is not helping us > understand as > >>> well as you seem to think it should. > >>> > >>> > --------------------------------------------------------------------------- > >>> Jeff Newmiller The ..... ..... Go > >>> Live... > >>> DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live > >>> Go... > >>> Live: OO#.. Dead: OO#.. Playing > >>> Research Engineer (Solar/Batteries O.O#. #.O#. with > >>> /Software/Embedded Controllers) .OO#. .OO#. > >>> rocks...1k > >>> > >>> > --------------------------------------------------------------------------- > >>> Sent from my phone. Please excuse my brevity. > >>> > >>> On April 5, 2015 9:52:18 AM PDT, John Wasige <johnwas...@gmail.com> > >>> wrote: > >>>> Thanks Bert, > >>>> > >>>> The structure of the data is a raster stack with nraw=867, Ncol=995 > >>>> > >>>> Rgds John > >>>> > >>>> > >>>> On Sun, Apr 5, 2015 at 6:39 PM, Bert Gunter <gunter.ber...@gene.com> > >>>> wrote: > >>>> > >>>>> See ?tapply > >>>>> > >>>>> However, as John said, without knowing the structure of your data, it > >>>>> is impossible to provide a guaranteed recipe. For example, does the > >>>>> data structure contain date information? -- it would be difficult > >>>> (but > >>>>> not impossible depending on data structure) to aggregate by calendar > >>>>> (bi-monthly, depending on your meaning of "bi") without knowing the > >>>>> months. Aggregating by every n days would be easy, but that's > >>>> probably > >>>>> not what you want. > >>>>> > >>>>> Cheers, > >>>>> Bert > >>>>> > >>>>> Bert Gunter > >>>>> Genentech Nonclinical Biostatistics > >>>>> (650) 467-7374 > >>>>> > >>>>> "Data is not information. Information is not knowledge. And knowledge > >>>>> is certainly not wisdom." > >>>>> Clifford Stoll > >>>>> > >>>>> > >>>>> > >>>>> > >>>>> On Sun, Apr 5, 2015 at 9:13 AM, John Kane <jrkrid...@inbox.com> > >>>> wrote: > >>>>>> Someone might if they had any idea of what the data actually looked > >>>> like > >>>>> and what you are trying to do. The 'bimonthly' for example, is > >>>> ambiguous in > >>>>> English; do you mean every two months or twice a month? > >>>>>> > >>>>>> Have a look at > >>>> https://github.com/hadley/devtools/wiki/Reproducibility > >>>>> and > >>>>> > >>>> > >>> > http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example > >>>>> with special attention to dput() as a method of supplying sample data > >>>> to > >>>>> the help list. > >>>>>> > >>>>>> John Kane > >>>>>> Kingston ON Canada > >>>>>> > >>>>>> > >>>>>>> -----Original Message----- > >>>>>>> From: johnwas...@gmail.com > >>>>>>> Sent: Sun, 5 Apr 2015 11:34:30 +0200 > >>>>>>> To: r-help@r-project.org > >>>>>>> Subject: [R] Aggregating daily rainfall raster data to bimontly > >>>> data > >>>>>>> > >>>>>>> Dear community, > >>>>>>> > >>>>>>> I have daily rainfall raster data for 30 years (1982_2011). I > >>>> would like > >>>>>>> to > >>>>>>> aggregate daily to bimonthly raster data. Could somebody kindly > >>>> help on > >>>>>>> how > >>>>>>> to go about it! > >>>>>>> > >>>>>>> Thanks for your help > >>>>>>> > >>>>>>> -- > >>>>>>> John > >>>>>>> > >>>>>>> [[alternative HTML version deleted]] > >>>>>>> > >>>>>>> ______________________________________________ > >>>>>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > >>>>>>> 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. > >>>>>> > >>>>>> ____________________________________________________________ > >>>>>> FREE ONLINE PHOTOSHARING - Share your photos online with your > >>>> friends > >>>>> and family! > >>>>>> Visit http://www.inbox.com/photosharing to find out more! > >>>>>> > >>>>>> ______________________________________________ > >>>>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > >>>>>> 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. > >>>>> > >>>> > >>>> [[alternative HTML version deleted]] > >>>> > >>>> ______________________________________________ > >>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > >>>> 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 -- To UNSUBSCRIBE and more, see > >>> 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. > >>> > >> > >> > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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. > > David Winsemius > Alameda, CA, USA > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.