> I'm trying to get the proportion "true" for dichotomous variable for various > subgroups in a survey.
Sorry, I'm new to the list, and just saw the advice about minimally reproducible code. Here goes: library(survey) foo <- data.frame(id = 1:25, weight = runif(25), year = rep(2002:2006, 5), problem = rnorm(25) > 0) foo.dsn = svydesign(id=~id, weight=~weight, data=foo) svyby(~problem, ~year, foo.dsn, svymean, na.rm=TRUE) # Fine # One year is missing foo[foo$year == 2004, "problem"] = NA foo.dsn = svydesign(id=~id, weight=~weight, data=foo) svyby(~problem, ~year, foo.dsn, svymean, na.rm=TRUE) # Error thanks alex Please access the attached hyperlink for an important electronic communications disclaimer: http://lse.ac.uk/emailDisclaimer ______________________________________________ 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.