What does this produce? > readLines("YourCSVfilename.csv", n=5)
If the data are in Excel, the date format used in .csv files is not always in the same as the format used when viewing dates in the spreadsheet. ------------------------------------- David L Carlson Department of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Shivi Bhatia Sent: Tuesday, July 26, 2016 7:42 AM To: Marc Schwartz Cc: R-help Subject: Re: [R] Date Time in R Thanks Marc for the help. this really helps. I think there is some issue with the data saved in csv format for this variable as when i checked: str(eir$date)- this results in :- Date[1:5327], format: NA NA NA NA NA. Thanks again. On Tue, Jul 26, 2016 at 5:58 PM, Marc Schwartz <marc_schwa...@me.com> wrote: > Hi, > > That eir$date might be a factor is irrelevant. There is an as.Date() > method for factors, which does the factor to character coercion internally > and then calls as.Date.character() on the result. > > Using the example data below: > > eir <- data.frame(date = c("05-30-16", "05-30-16", "05-30-16", > "05-30-16", "05-30-16", "05-30-16")) > > > str(eir) > 'data.frame': 6 obs. of 1 variable: > $ date: Factor w/ 1 level "05-30-16": 1 1 1 1 1 1 > > > eir > date > 1 05-30-16 > 2 05-30-16 > 3 05-30-16 > 4 05-30-16 > 5 05-30-16 > 6 05-30-16 > > eir$date <- as.Date(eir$date, format = "%m-%d-%y") > > > str(eir) > 'data.frame': 6 obs. of 1 variable: > $ date: Date, format: "2016-05-30" ... > > > eir > date > 1 2016-05-30 > 2 2016-05-30 > 3 2016-05-30 > 4 2016-05-30 > 5 2016-05-30 > 6 2016-05-30 > > eir$days <- weekdays(eir$date) > > > str(eir) > 'data.frame': 6 obs. of 2 variables: > $ date: Date, format: "2016-05-30" ... > $ days: chr "Monday" "Monday" "Monday" "Monday" ... > > > eir > date days > 1 2016-05-30 Monday > 2 2016-05-30 Monday > 3 2016-05-30 Monday > 4 2016-05-30 Monday > 5 2016-05-30 Monday > 6 2016-05-30 Monday > > > I would check to be sure that you do not have any typos in your code. > > Regards, > > Marc Schwartz > > > > On Jul 26, 2016, at 6:58 AM, Shivi Bhatia <shivipm...@gmail.com> wrote: > > > > Hello Again, > > > > While i tried your solution as you suggested above it seems to be > working. > > Here is the output > > temp<- dput(head(eir$date)) > > c("05-30-16", "05-30-16", "05-30-16", "05-30-16", "05-30-16", "05-30-16") > > however it still shows class(eir$date) as character and hence i cannot > find > > weekdays from this variable. > > > > Sorry but i still dont understand in totality how R reads dates even > though > > have tried enough. > > > > Regards, Shivi > > > > > > On Tue, Jul 26, 2016 at 5:12 PM, Shivi Bhatia <shivipm...@gmail.com> > wrote: > > > >> Thanks Duncan for the quick response. I will check again as you > suggested. > >> If that doesn't work i will share a reproducible example. > >> > >> Thanks again!!!! > >> > >> On Tue, Jul 26, 2016 at 4:43 PM, Duncan Murdoch < > murdoch.dun...@gmail.com> > >> wrote: > >> > >>> On 26/07/2016 7:05 AM, Shivi Bhatia wrote: > >>> > >>>> Hi Team, > >>>> > >>>> This scenario may have come across a number of times however i checked > >>>> nabble & SO and couldn't find a solution hence request assistance. > >>>> > >>>> I have a date variable in my data-set eir. The class of this var was > >>>> character while i had read the file in r studio. Example of date - > >>>> 05-30-16 > >>>> > >>>> To change this i have used eir$date<- as.Date(eir$date, "%m-%d-%y"). > This > >>>> converts it to a date variable. However when i check few obs > >>>> with head(eir$date) all the results are <NA>. > >>>> > >>> > >>> I think you don't have character data like that, because I see > >>> > >>>> as.Date("05-30-16", "%m-%d-%y") > >>> [1] "2016-05-30" > >>> > >>> I'd guess eir$date is really a factor, because character data is > >>> frequently changed to factor automatically. If that's the case, this > >>> should work for the conversion: > >>> > >>> as.Date(as.character(eir$date), "%m-%d-%y") > >>> > >>> If that doesn't work, you'll need to post something reproducible. > >>> > >>> Duncan Murdoch > >>> > >>> I also need to create weekdays from this date variable but until i get > >>>> this > >>>> resolved i cant find a weekday. For weekday i have used: > >>>> eir$week<- (eir$date) > >>>> eir$week<- weekdays(as.Date(eir$week)) > >>>> class(eir$week) > >>>> eir$week<- as.factor(eir$week) > >>>> head(eir$week) > >>>> > >>>> Head of this eir$week results again as expected in <NA> but shows > Levels: > >>>> Friday Monday Saturday Sunday Thursday Tuesday Wednesday > >>>> > >>>> Not sure what i should do here. Kindly suggest. > > [[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.