Dear David, Subsetting works but the 'date' information is lost in the new file.
Thanks, Mike. I was not aware of the bug but will work on learning about (getZ) and (setZ). Thanks again! Sincerely, Milu On Tue, Jun 19, 2018 at 7:32 AM, Michael Sumner <mdsum...@gmail.com> wrote: > > > On Mon, 18 Jun 2018, 22:09 David Winsemius, <dwinsem...@comcast.net> > wrote: > >> >> >> > On Jun 18, 2018, at 7:21 AM, Miluji Sb <miluj...@gmail.com> wrote: >> > >> > Dear all, >> > >> > I have a rasterbrick with the date/time information provided which I >> would >> > like to subset by year. >> > >> > However, when I use the following code for sub-setting; >> > >> > new_brick <- subset(original, which(getZ( original ) >= >> as.Date("2000-01-01 >> > 10:30:00") & getZ(original ) <= as.Date("2014-12-31 10:30:00"))) >> > >> > The date/time information seems to be lost. >> > >> > > This is a bug, I tend to extract (getZ) the dates, do the subset logic on > both and restore (setZ). > > It takes a bit of learning and practice, good luck. I can't expand more at > the moment. See R-Sig-Geo for more specific discussion forum, and #rstats > on twitter is really good. > > Cheers, Mike > >> > Furthermore, the class of the date/time seems to be character; >> > >> > ## >> > class(getZ( original )) >> > [1] "character" >> > >> > Is it possible to convert this string to date before sub-setting or >> retain >> > the date/time information after sub-setting? >> >> Yes, it is certainly possible, but why bother? R's Comparison operators >> work on character values so you should be able to do this (if the >> subsetting is syntactically correct: >> >> new_brick <- subset(original, which(getZ( original ) >= "2000-01-01 >> 10:30:00" & getZ(original ) <= "2014-12-31 10:30:00") ) >> >> >> As always if you had presented the output of dput(head(original)) >> assuming that head is a meaningful operation on such an object, the >> demonstration would have been possible. An alternate would be to offer a >> library call to a package and then load a relevant example. >> >> >> Best; >> David >> > >> > ### original RasterBrick ### >> > class : RasterBrick >> > dimensions : 600, 1440, 864000, 11320 (nrow, ncol, ncell, nlayers) >> > resolution : 0.25, 0.25 (x, y) >> > extent : -180, 180, -60, 90 (xmin, xmax, ymin, ymax) >> > coord. ref. : +proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0 >> > data source : >> > /work/mm01117/GLDAS_025_deg/daily/gldas_tavg_tmin_tmax_ >> precip_windspd_sphum_daily_1986_2016.nc4 >> > names : X1986.01.01.10.30.00, X1986.01.02.10.30.00, >> > X1986.01.03.10.30.00, X1986.01.04.10.30.00, X1986.01.05.10.30.00, >> > X1986.01.06.10.30.00, X1986.01.07.10.30.00, X1986.01.08.10.30.00, >> > X1986.01.09.10.30.00, X1986.01.10.10.30.00, X1986.01.11.10.30.00, >> > X1986.01.12.10.30.00, X1986.01.13.10.30.00, X1986.01.14.10.30.00, >> > X1986.01.15.10.30.00, ... >> > Date/time : 1986-01-01 10:30:00, 2016-12-31 10:30:00 (min, max) >> > varname : v1 >> > >> > ### new RasterBrick ### >> > class : RasterStack >> > dimensions : 600, 1440, 864000, 5477 (nrow, ncol, ncell, nlayers) >> > resolution : 0.25, 0.25 (x, y) >> > extent : -180, 180, -60, 90 (xmin, xmax, ymin, ymax) >> > coord. ref. : +proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0 >> > names : X2000.01.01.10.30.00, X2000.01.02.10.30.00, >> > X2000.01.03.10.30.00, X2000.01.04.10.30.00, X2000.01.05.10.30.00, >> > X2000.01.06.10.30.00, X2000.01.07.10.30.00, X2000.01.08.10.30.00, >> > X2000.01.09.10.30.00, X2000.01.10.10.30.00, X2000.01.11.10.30.00, >> > X2000.01.12.10.30.00, X2000.01.13.10.30.00, X2000.01.14.10.30.00, >> > X2000.01.15.10.30.00, ... >> > >> > Any help will be greatly appreciated. >> > >> > Sincerely, >> > >> > Milu >> > >> > [[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. >> > -- > Dr. Michael Sumner > Software and Database Engineer > Australian Antarctic Division > 203 Channel Highway > <https://maps.google.com/?q=203+Channel+Highway+Kingston+Tasmania+7050+Australia&entry=gmail&source=g> > Kingston Tasmania 7050 Australia > <https://maps.google.com/?q=203+Channel+Highway+Kingston+Tasmania+7050+Australia&entry=gmail&source=g> > > [[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.