Hi Duncan, I have converted the string to a POSIXIt object using
> strptime('31-may-2014',format="%d-%b-%Y") But could not figure out the way forward. Could you please elaborate a bit? On Fri, Oct 10, 2014 at 5:14 PM, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > On 10/10/2014, 7:28 AM, Abhinaba Roy wrote: > > Hi R helpers, > > > > I want to write a function which will > > > > 1. Count the number of fridays in the current month ( to extract month > from > > given date) and also the number of fridays in the preceeding month > > > > 2. Calculate the ratio of the number of fridays in current month to the > > number of fridays in the precceding month > > > > 3. Return a integer value calculated as > > ifelse(ratio>1,1,ifesle(ration<1,-1),0) > > > > The date which is passed is in the format *'31-may-2014'* > > > > So, given the date '31-may-2014' > > > > Number of fridays in May2014 = 5 > > Number of fridays in Apr2014 = 4 > > > > Ratio = 5/4 >1 > > Hence, the function will return a value 1 > > > > I want to call the function by passing '31-may-2014' as an argument > > > > How can this be done in R? > > > > Any help will be appreciated > > Convert your string to a POSIXlt object using as.POSIXlt. Then you can > extract year, month and weekday from the result, and go from there. > (The only unobvious part is figuring out how many days are in each > month, but there are questions online giving various ways to do this.) > > Duncan Murdoch > > [[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.