On Nov 7, 2011, at 9:39 AM, Paul Miller wrote:
Hello All,
I've been reading books about R for awhile now and am in the process
of replicating the SAS analyses from an old report. I want to be
sure that I can do all the things I need to in R before using it in
my daily work.
So far, I've managed to read in all my data and have done some data
manipulation. I'm having trouble with fixing an error in a date
variable though, and was hoping someone could help.
One of the patients in my data has a DOB incorrectly entered as:
'11/23/21931'
Their DOB should be:
'11/23/1931'
How can I correct this problem before calculating age in the code
below?
DOB starts out as a factor in the Demo dataframe but then is
converted into a date. So I had thought the ifelse that follows
could be used to correct the problem, but this doesn't seem to be
the case.
Thanks,
Paul
Why not fix the single error first?
Demo[ Demo$Subject==108945, "DateCompleted"] <- '11/23/1931'
Then you can skip the time-consuming ifelse() inside the within() call.
--
David
Demo_Char <- within(Demo, {
DateCompleted <- as.Date(DateCompleted, format = "%m/%d/%Y")
DOB <- as.Date(DOB, format = "%m/%d/%Y")
DOB <- ifelse(Subject==108945, as.Date("1931-11-23"), DOB)
Age <- as.integer((DateCompleted - DOB) / 365.25)
})
______________________________________________
[email protected] 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.
David Winsemius, MD
West Hartford, CT
______________________________________________
[email protected] 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.
