Thank you Deepayan. Your suggestion worked perfectly. Thanks too to Gabor for your suggestion and for your help trying to get this help request through to r-help before I subscribed.
I'm all set now. Gary On Sat, Aug 1, 2009 at 1:17 PM, Deepayan Sarkar<deepayan.sar...@gmail.com> wrote: > On Sat, Aug 1, 2009 at 7:26 AM, Gary Lewis<gary.m.le...@gmail.com> wrote: >> I could use some advice regarding xyplot. >> >> I've got 2 time series. Both cover approximately the same period of >> time (ie, 1940 to 2009). But one series has annual data and the other >> has monthly data. One refers to university enrollment; the other to >> unemployment rates. Both are currently in the same data frame. >> >> I'd like to use the monthly times series as a light grayscale >> background for a plot of the annual time series, showing both series >> as type "l" (line). Naturally with all the NA's in the annual series, >> that plot disappears because points are not connected across missing >> values. > > You could define a small wrapper function that discards NA's before > drawing lines: > > my.panel.lines <- function(x, y, ...) { > keep <- !is.na(y) > panel.lines(x[keep], y[keep], ...) > } > > and use it as a custom panel.groups function: > > xyplot(<whatever you had before>, > panel = panel.superpose, panel.groups = my.panel.lines) > > -Deepayan > >> I suppose I could make both series annual, but a lot of interesting >> detail would get lost this way. Or I guess I could interpolate values >> in the annual series with monthly approximations, but this means 11 >> out of every 12 values is an approximation. Or I suppose I could plot >> each series separately and then print them with position information, >> which I'm reluctant to do because panel.superpose so nicely handles >> the alignment of the 2 panels. >> >> What I'd really like to do is plot each independently but still >> superposed. Effectively this seems to mean monthly data intervals but >> line connections across the NA's in the series with annual intervals. >> >> Any suggestions would be appreciated. Thanks. >> >> Gary Lewis >> >> ______________________________________________ >> 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.