POSIXlt stores the date-times as a list of vectors decomposed into the
(still numeric) component parts ("sec", "min", "hour", "mday", "mon",
"year", "wday", "yday", "isdst") so that cannot be stored as a single
column in the data frame - you would need 9 columns.Compare these to see the underlying structure: tm <- Sys.time() ## POSIXct unclass(tm) ## POSIXlt unclass(as.POSIXlt(tm)) You can just cast to character, directly or with format - see ?strptime for the full set of format tokens available. For example: as.character(tm) ##[1] "2009-12-31 07:28:01" format(tm, "%Y/%b/%a %H:%M:%S") ##[1] "2009/Dec/Thu 07:28:01" Hope that helps. Regards, Mike. On Thu, Dec 31, 2009 at 7:15 AM, Agustin Lobo <alobolis...@gmail.com> wrote: > This might be a bit off-topic. > I have to export as shape an Sp.Poly.DF in which > one of the variables records date and time as POSIXtc. As > writeOGR() complains about the POSIXct variable, I'm > trying to convert to POSIXlt, which I think that will be > accepted (another alternative would be coverting to an > string char, but prefer to keep the SPDF object with > a correct class definition for that variable). > Let's call patata the table of the SPDF. > >> class(patata$Tima) > [1] "POSIXt" "POSIXct" > >> patata$Tima[1] > [1] "2009-09-26 09:57:24 CEST" > >> as.POSIXlt(patata$Tima[1]) > [1] "2009-09-26 09:57:24 CEST" > >> class(as.POSIXlt(patata$Tima[1])) > [1] "POSIXt" "POSIXlt" > > So I was happy, but: > >> patata$Tima <- as.POSIXlt(patata$Tima) > Error in `$<-.data.frame`(`*tmp*`, "Tima", value = list(sec = c(24, 33, : > replacement has 9 rows, data has 44 > Calls: $<- -> $<-.data.frame > > > Is there any way I can put the POSIXlt object in the table (patata) of the > SPDF object? > > Thanks! > > Agus > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
