and is it not possible to ignore savings time? My data are in UTC, with no savings time changes > delme = strptime(aur2009[,1], "%m/%d/%Y %H:%M",tz="UTC") > any(duplicated(delme)) [1] TRUE
> delme = as.POSIXct(aur2009[,1], "%m/%d/%Y %H:%M",tz="UTC") > any(duplicated(delme)) [1] TRUE Agus On Wed, May 18, 2011 at 8:55 AM, Michael Sumner <mdsum...@gmail.com> wrote: > See under "Note" in ?strptime: > Remember that in most timezones some times do not occur and some > occur twice because of transitions to/from summer time. > ‘strptime’ does not validate such times (it does not assume a > specific timezone), but conversion by ‘as.POSIXct’) will do so. > > > > On Wed, May 18, 2011 at 3:53 PM, Agustin Lobo <agustin.l...@ictja.csic.es> > wrote: >> >> I have a problem with duplicated date_time stamps that I do not see as >> duplicated. >> >> I read a file with observations taken every 30 minutes: >> >> > >> > aur2009=read.csv(paste(datadir,"AUR_ECPP_2009.csv",sep="/"),sep=";",stringsAsFactors=F) >> > aur2009[1:3,1:5] >> Date.Time E_filled E_filled_flag LE_filled LE_filled_flag >> 1 1/1/2009 0:00 0 NaN 5.86 NaN >> 2 1/1/2009 0:30 0 NaN 5.05 NaN >> 3 1/1/2009 1:00 0 NaN 5.56 NaN >> >> > delme = strptime(aur2009[,1], "%m/%d/%Y %H:%M") >> > aur2009[,1]=as.POSIXct(delme) >> Date.Time E_filled E_filled_flag LE_filled LE_filled_flag >> 1 2009-01-01 00:00:00 0 NaN 5.86 NaN >> 2 2009-01-01 00:30:00 0 NaN 5.05 NaN >> 3 2009-01-01 01:00:00 0 NaN 5.56 NaN >> >> > aur2009ts = ts(aur2009) >> > row.names(aur2009ts) = as.character(delme) >> > aur2009ts[1:3,1:5] >> Date.Time E_filled E_filled_flag LE_filled >> LE_filled_flag >> 2009-01-01 00:00:00 1230764400 0 NaN 5.86 >> NaN >> 2009-01-01 00:30:00 1230766200 0 NaN 5.05 >> NaN >> 2009-01-01 01:00:00 1230768000 0 NaN 5.56 >> NaN >> >> Then: >> > aur2009z = zoo(aur2009[,2:12],as.POSIXct(delme)) >> Warning message: >> In zoo(aur2009[, 2:12], as.POSIXct(delme)) : >> some methods for “zoo” objects do not work if the index entries in >> ‘order.by’ are not unique >> >> So I investigate: >> > any(duplicated(aur2009ts[,1])) >> [1] TRUE >> >> > aur2009ts[(duplicated(aur2009ts[,1])),1:5] >> Date.Time E_filled E_filled_flag LE_filled >> LE_filled_flag >> 2009-03-29 02:00:00 1238284800 0 NaN 1.2 >> NaN >> 2009-03-29 02:30:00 1238286600 0 NaN 1.2 >> NaN >> >> But note the surprise: >> > aur2009ts[aur2009ts[,1]==1238284800,1:5] >> Date.Time E_filled E_filled_flag LE_filled >> LE_filled_flag >> 2009-03-29 01:00:00 1238284800 0 NaN -0.58 >> NaN >> 2009-03-29 02:00:00 1238284800 0 NaN 1.20 >> NaN >> > aur2009ts[aur2009ts[,1]==1238286600,1:5] >> Date.Time E_filled E_filled_flag LE_filled >> LE_filled_flag >> 2009-03-29 01:30:00 1238286600 0 NaN -0.34 >> NaN >> 2009-03-29 02:30:00 1238286600 0 NaN 1.20 >> NaN >> >> The dates detected as duplicated are actually different times that got >> the same value in the ts version of the object! >> What am I doing wrong? They are all observations every 30min, why are >> these 2 encoded as the >> same time? >> >> Any help appreciated >> >> Agus >> >> ______________________________________________ >> 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. > > > > -- > Michael Sumner > Institute for Marine and Antarctic Studies, University of Tasmania > Hobart, Australia > e-mail: mdsum...@gmail.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.
