The situation he is referring to seems to be this: > L <- "date,value\n'2009-01-01',10\n'2009-02-01',1\n'NA', 3" > read.csv(textConnection(L), colClasses = c("Date", "numeric")) Error in charToDate(x) : character string is not in a standard unambiguous format
where all the fields in the date column are quoted. On Wed, Nov 25, 2009 at 2:56 PM, jim holtman <jholt...@gmail.com> wrote: > Seems to work fine in my testing: > >> x <- read.csv(textConnection("date,value > + 2009-01-01,10 > + 2009-02-01,1 > + 'NA', 3"), colClasses=c("Date", 'integer')) >> >> str(x) > 'data.frame': 3 obs. of 2 variables: > $ date :Class 'Date' num [1:3] 14245 14276 NA > $ value: int 10 1 3 >> x <- read.csv(textConnection("date,value > + 2009-01-01,10 > + 2009-02-01,1 > + NA, 3"), colClasses=c("Date", 'integer')) >> >> str(x) > 'data.frame': 3 obs. of 2 variables: > $ date :Class 'Date' num [1:3] 14245 14276 NA > $ value: int 10 1 3 >> > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > On Wed, Nov 25, 2009 at 12:38 PM, > <nabble.30.miller_2...@spamgourmet.com> wrote: >> Hello - >> >> I have a csv file with a few date columns. Some of the records have an >> "NA" character string instead of the date. When I attempt to use >> read.csv() and typecast the columns using colClasses, I receive the >> following error: >> Error in charToDate(x) : >> character string is not in a standard unambiguous format >> >> Similarly, the following command produces the same error: >> as.Date("NA") >> >> However, as.Date(NA) performs as documented. >> >> Can we enhance the as.Date() function to convert "NA" strings into NA >> value prior to type conversion? >> >> Thanks! ______________________________________________ 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.