Thanks Tom for the recommendation. This is now working. Apologies if this sounds like a juvenile but i am not very good with dates in R. What i initially did when i saw date as factor and then tried converting with lot many transformation that is where it went bad.
But thanks to all this is really what i wanted. On Tue, Jul 26, 2016 at 9:58 PM, Tom Wright <t...@maladmin.com> wrote: > So this looks correct so far. > > > > # convert strings (or factors) to a date object > > a1$date <- as.Date(a1$date, “%m-%d-%y”) > > > > # Note the date object is now displayed in the format %Y-%m-%d by default > > # so no need for the mdy() or ymd() function > > > > # extract the weekdays as number > > weekdays <- wday(a1$date) > > > > # note can’t have spaces in variable names > > week_names <- wday(a1$date, label=TRUE) > > > > > > *From:* Shivi Bhatia [mailto:shivipm...@gmail.com] > *Sent:* July 26, 2016 12:16 PM > *To:* Tom Wright <t...@maladmin.com> > *Cc:* David L Carlson <dcarl...@tamu.edu>; r-help <r-help@r-project.org> > > *Subject:* Re: [R] Date Time in R > > > > Hello Tom, > > > > Please find the details: (i have changed name from eir to a1, rest all is > same) > > > > str(a1$date) > > Factor w/ 32 levels "05-30-16","05-31-16",..: 1 1 1 > > > > head(a1$date) > > 05-30-16 05-30-16 05-30-16 05-30-16 05-30-16 05-30-16 > > 32 Levels: 05-30-16 05-31-16 06-01-16 06-02-16 06-03-16 06-04-16 06-05-16 > 06-06-16 06-07-16 06-08-16 > > > > Thanks again!!! > > > > On Tue, Jul 26, 2016 at 9:38 PM, Tom Wright <t...@maladmin.com> wrote: > > Hi again Shiva, > I think what we need to see is the output from: > > str(eid$date) > > and perhaps > head(eid$date) > > If you can send this information before doing any processing on the date > (i.e. before the as.Date() function) we may be able to help. > > > > -----Original Message----- > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Shivi > Bhatia > Sent: July 26, 2016 11:46 AM > To: David L Carlson <dcarl...@tamu.edu> > Cc: r-help <r-help@r-project.org> > Subject: Re: [R] Date Time in R > > Hi David please see the code and some reproducible data: > eir$date<- as.Date(eir$date,format = "%m-%d-%y") then i had used the > lubridate library to help with the dates: > install.packages("lubridate") > library(lubridate) > eir$date <- mdy(eir$date) > weekdays <- wdy(eir$date) > week names <- wdy(eir$date, label = TRUE) > > This the output from the file: > > structure(list(date = structure(c(NA_real_, NA_real_, NA_real_), class = > "Date"), > > month = structure(c(2L, 2L, 2L), .Label = c("Jun","May"), class = > "factor"), > > day = c(30L, 30L, 30L), > > weekday = structure(c(2L,2L, 2L), .Label = c("Fri", "Mon", "Sat", "Sun", > "Thu", "Tue","Wed"), class = "factor"), > > survey_rating = c(3L, 2L, 3L), query_status = c("Yes", "Don't know","No"), > > a = c("05-30-16", "05-30-16", "05-30-16")), .Names = c("date","month", > "day", "weekday", "survey_rating"), row.names = c(NA, 3L), class = > "data.frame") > > There are several other variables that i have removed which are not > relevant > in this context. > > On Tue, Jul 26, 2016 at 8:55 PM, David L Carlson <dcarl...@tamu.edu> > wrote: > > > Show us the output, don’t just tell us what you are seeing. If the > > dates are correct in the csv file, show us the structure of the data > > frame you created with read.csv() and show the command(s) you used to > > convert the character data to date format. The solution is likely to > > be simple if you will cut/paste the R console and not just describe what > > is happening. > > > > > > > > David C > > > > > > > > > *From:* Shivi Bhatia [mailto:shivipm...@gmail.com] > > *Sent:* Tuesday, July 26, 2016 10:08 AM > > *To:* David L Carlson > > > > *Subject:* Re: [R] Date Time in R > > > > > > > > > Hi David, > > > > This gives the results accurately. The first line shows all the > > variable names and the rest shows all values stored for each of the > > variable. Here date is appearing as correct. > > > > > > > > Thanks, Shivi > > > > > > > > On Tue, Jul 26, 2016 at 7:39 PM, David L Carlson <dcarl...@tamu.edu> > > wrote: > > > > 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 > > > <https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mai > > lman_listinfo_r-2Dhelp&d=CwMFaQ&c=ODFT-G5SujMiGrKuoJJjVg&r=veMGHMCNZSh > > ld-KX-bIj4jRE_tP9ojUvB_Lqp0ieSdk&m=s9RjgM0-LqObg32B_ODUoHMjaBJSYFn0ccx > > orF0VRaQ&s=-2AvIVGKBvHIg4b3KBUCarOh98Mq95XbBM6rQR5o_Qw&e=> > > PLEASE do read the posting guide > > http://www.R-project.org/posting-guide.html > > <https://urldefense.proofpoint.com/v2/url?u=http-3A__www.R-2Dproject.o > > rg_posting-2Dguide.html&d=CwMFaQ&c=ODFT-G5SujMiGrKuoJJjVg&r=veMGHMCNZS > > hld-KX-bIj4jRE_tP9ojUvB_Lqp0ieSdk&m=s9RjgM0-LqObg32B_ODUoHMjaBJSYFn0cc > > xorF0VRaQ&s=Ldb33UyU9KMUXEsxxzwItyCFjZInukICij2jo66xaKg&e=> > > > and provide commented, minimal, self-contained, reproducible code. > > > > > > > > [[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. > > > [[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.
