Do you mean merge them into a two column series of price for one column and change for another column? That is what I will assume since the result was not illustrated.
Suggest you read the help files and the three vignettes in the zoo package. Also R News 4/1 has info on dates. If you were looking for OHLC representations then see the xts package which in turn uses zoo and read its documentation in addition to the above. library(zoo) # ensure you are using zoo 1.5.0 or later price.Lines <- "Year month day price 1990 8 20 119.1 1990 8 27 124.5 1990 9 3 124.2 1990 9 10 125.2 1990 9 17 126.6 1990 9 24 127.2 1990 10 1 132.1 1990 10 8 133.3 1990 10 15 133.9 1990 10 22 134.5 1990 10 29 133.9 2008 3 3 313.7 2008 3 10 320 2008 3 17 325.7 2008 3 24 322.4 " price.DF <- read.table(textConnection(price.Lines), header = TRUE) price <- with(price.DF, zoo(price, as.Date(paste(Year, month, day, sep = "-")))) change.Lines <- "M-Y Year Month Change Aug-1990 1990 8 -226.871 Sep-1990 1990 9 -896.333 Oct-1990 1990 10 111.419 Nov-1990 1990 11 -364.2 Dec-1990 1990 12 -527.645 Jan-1991 1991 1 -70.935 Feb-1991 1991 2 231.214 Mar-1991 1991 3 -239 " change <- read.zoo(textConnection(change.Lines), header = TRUE, FUN = as.yearmon, format = "%b-%Y", colClasses = c("character", "NULL", "NULL", "numeric")) # convert change series to Date using last of month as the date time(change) <- as.Date(time(change), frac = 1) merge(price, change) On Sun, Mar 30, 2008 at 11:24 AM, Richard Saba <[EMAIL PROTECTED]> wrote: > > I have weekly time series data with year, month, day, and price variables. > The input data set for the weekly series takes the following form: > > Year month day price > 1990 8 20 119.1 > 1990 8 27 124.5 > 1990 9 3 124.2 > 1990 9 10 125.2 > 1990 9 17 126.6 > 1990 9 24 127.2 > 1990 10 1 132.1 > 1990 10 8 133.3 > 1990 10 15 133.9 > 1990 10 22 134.5 > 1990 10 29 133.9 > .. ... ... ... > ... ... .... .... > 2008 3 3 313.7 > 2008 3 10 320 > 2008 3 17 325.7 > 2008 3 24 322.4 > > > I would like to collapse the data into monthly averages to merge with a > monthly series. The input data set for the monthly series takes the > following form: > > M-Y Year Month Change > Aug-1990 1990 8 -226.871 > Sep-1990 1990 9 -896.333 > Oct-1990 1990 10 111.419 > Nov-1990 1990 11 -364.2 > Dec-1990 1990 12 -527.645 > Jan-1991 1991 1 -70.935 > Feb-1991 1991 2 231.214 > Mar-1991 1991 3 -239 > > ... ... ..... .. .... > > > The merged data set should be of class(ts). > I can perform the conversions outside of R and then import but I would > rather perform all conversions within R. I have looked through the zoo and > Rmetrics packages but without success. > > Any help will be appreciated. > Thanks, > > Richard Saba > Department of Economics > Auburn University > Email: [EMAIL PROTECTED] > Phone: 334 844-2922 > > ______________________________________________ > 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. > ______________________________________________ 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.