Please don't post files to nabble in the future -- when Nabble removes them, we then have a broken link in the real archives: dput() is much preferred way to send data.
Anyways: # mydata <- read.csv("http://r.789695.n4.nabble.com/file/n4638691/jan_2011.csv") # # dput(head(mydata, 15)) structure(list(Delivery.Date = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("01/01/2011", "01/02/2011", "01/03/2011", "01/04/2011", "01/05/2011", "01/06/2011", "01/07/2011", "01/08/2011", "01/09/2011", "01/10/2011", "01/11/2011", "01/12/2011", "01/13/2011", "01/14/2011", "01/15/2011", "01/16/2011", "01/17/2011", "01/18/2011", "01/19/2011", "01/20/2011", "01/21/2011", "01/22/2011", "01/23/2011", "01/24/2011", "01/25/2011", "01/26/2011", "01/27/2011", "01/28/2011", "01/29/2011", "01/30/2011", "01/31/2011" ), class = "factor"), Hour.Ending = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L), .Label = c("01:00", "02:00", "03:00", "04:00", "05:00", "06:00", "07:00", "08:00", "09:00", "10:00", "11:00", "12:00", "13:00", "14:00", "15:00", "16:00", "17:00", "18:00", "19:00", "20:00", "21:00", "22:00", "23:00", "24:00"), class = "factor"), Repeated.Hour.Flag = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "N", class = "factor"), Settlement.Point = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 12L, 13L, 14L, 1L), .Label = c("HB_BUSAVG", "HB_HOUSTON", "HB_HUBAVG", "HB_NORTH", "HB_SOUTH", "HB_WEST", "LZ_AEN", "LZ_CPS", "LZ_HOUSTON", "LZ_LCRA", "LZ_NORTH", "LZ_RAYBN", "LZ_SOUTH", "LZ_WEST"), class = "factor"), Settlement.Point.Price = c(25.18, 25.36, 25.07, 25.33, 25.12, 24.49, 25.2, 25.12, 25.41, 25.15, 25.32, 25.32, 25.1, 25.07, 23.84)), .Names = c("Delivery.Date", "Hour.Ending", "Repeated.Hour.Flag", "Settlement.Point", "Settlement.Point.Price" ), row.names = c(NA, 15L), class = "data.frame") mydata[,1] <- as.Date(mydata[,1], format = "%m/%d/%Y") works just fine for me. Note that you were missing a column. On Wed, Aug 1, 2012 at 9:21 AM, algotr8der <algotr8...@gmail.com> wrote: > I have an object, which I pull in from a csv file here > http://r.789695.n4.nabble.com/file/n4638691/jan_2011.csv jan_2011.csv > > mydata <- read.csv("jan_2011.csv", header=TRUE, sep=",") > >> head(mydata) > Delivery.Date Hour.Ending Repeated.Hour.Flag Settlement.Point > Settlement.Point.Price > 1 01/01/2011 01:00 N HB_BUSAVG > 25.18 > 2 01/01/2011 01:00 N HB_HOUSTON > 25.36 > 3 01/01/2011 01:00 N HB_HUBAVG > 25.07 > 4 01/01/2011 01:00 N HB_NORTH > 25.33 > 5 01/01/2011 01:00 N HB_SOUTH > 25.12 > 6 01/01/2011 01:00 N HB_WEST > 24.49 > >> str(mydata) > 'data.frame': 10416 obs. of 5 variables: > $ Delivery.Date : Factor w/ 31 levels "01/01/2011","01/02/2011",..: > 1 1 1 1 1 1 1 1 1 1 ... > $ Hour.Ending : Factor w/ 24 levels "01:00","02:00",..: 1 1 1 1 1 > 1 1 1 1 1 ... > $ Repeated.Hour.Flag : Factor w/ 1 level "N": 1 1 1 1 1 1 1 1 1 1 ... > $ Settlement.Point : Factor w/ 14 levels "HB_BUSAVG","HB_HOUSTON",..: > 1 2 3 4 5 6 7 8 9 10 ... > $ Settlement.Point.Price: num 25.2 25.4 25.1 25.3 25.1 ... > > I want to convert the Delivery.Date field to a date object. I tried various > attempts but failed with the following: > >> as.Date(mydata[1], "%m/%d/%Y") > Error in as.Date.default(ercot[1], "%m/%d/%Y") : > do not know how to convert 'ercot[1]' to class "Date" No idea where this "ercot" thing comes from. Best, Michael > > I even tried to save the first column to a separate object and tried the > same but got the same result. At this point I'm not sure how to move > forward. Appreciate the help. > > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/as-date-do-not-know-how-to-convert-test-1-to-class-Date-tp4638691.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.