Hello, I'm attempting to return the date (in form '%Y-%m-%d') of the Monday previous to the current date. For example: since it is 2011-09-02 today, I would expect 2011-08-29 to be the return value.
I found the following in: http://www.mail-archive.com/r-help@r-project.org/msg144184.html Start quote from link: prevmonday <- function(x) 7 * floor(as.numeric(x-1+4) / 7) + as.Date(1-4) For example, > prevmonday(Sys.Date()) [1] "2011-08-15" > prevmonday(prevmonday(Sys.Date())) [1] "2011-08-15" End quote from link. But when I do it I get: > prevmonday <- function(x) 7 * floor(as.numeric(x-1+4) / 7) + as.Date(1-4) > prevmonday(Sys.Date()) Error in as.Date.numeric(1 - 4) : 'origin' must be supplied I've tried setting the 'origin' argument in as.Date() in different ways, but it returns inaccurate results. Thanks, Ben [[alternative HTML version deleted]] ______________________________________________ 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.
