>>>>> "KKWa" == Ko-Kang Kevin Wang <k.wang at auckland.ac.nz>
>>>>> on Thu, 17 Jun 2004 19:57:39 +1200 writes:
KKWa> Hi,
KKWa> I've been playing with:
>> joinDate <- format(strptime(as.vector(forum[,2]), "%d-%b-%y"),
KKWa> + "%d-%b-%Y")
>> today <- format(strptime(as.vector("14-Jun-04"), "%d-%b-%Y"),
KKWa> + "%d-%b-%Y")
>> joinDate
KKWa> [1] "04-Feb-2004" "13-Feb-2004" "26-Feb-2004" "27-Feb-2004"
KKWa> "27-Feb-2004"
KKWa> [6] "27-Feb-2004" "29-Feb-2004" "01-Mar-2004" "02-Mar-2004"
KKWa> "07-Mar-2004"
KKWa> ................................
>> today
KKWa> [1] "14-Jun-0004"
>> joinDate - today
KKWa> Error in joinDate - today : non-numeric argument to binary operator
KKWa> But it didn't quite work. What I'd like joinDate -
KKWa> today to return is the number of days to today, since
KKWa> joinDate. I'm sure it has been asked before however a
KKWa> search on r-help didn't found me any relevant
KKWa> information *_*.
Kevin,
[[did you have tough day? usually your Q/A are much better ;-()]]
both joinDate and today are results of format() and hence
character vectors (with no time information left).
You didn't really expect "-" to work with characters?
OTOH, "-" properly does work with POSIX*t objects,
see, e.g., ?difftime
Regards,
Martin