Dear colleagues, I have a problem which has bitten me occasionally. I often need to prepare graphs for many variables in a data set, but seldom for all. or for any large number of sequential or sequentially named variables. Often I need several graphs for different subsets of the dataset for a given variable. I run into similar problems with other needs besides graphing.
What I would like to do is something like "write a function which takes the *name* of a variable, presumably a s a character string, from a dataframe, as one argument, and the dataframe, as a second argument". For example, where y is to be the the name of a variable in a given dataframe d, and the other variables needed, T, M and so on, are to be found in the same dataframe :- pf <- function (y,data,...) { p1 <- xyplot(y~x|T,data) p2 <- xyplot(y~x|T,subset(data,M == 2)) p3 <- xyplot(y~x|T,subset(data,M == 4)) #print(p1,p2,p3....) } pf(Score1,data) pf(Score2,data) This fails, because, of course, Score 1, Score 2 etc.. are not defined, or if you pass them as pf(data$Score2,data), then when you subset the data, data$Score2 is now the wrong shape. I've come up with various inelegant hacks, (often with for loops), for getting around this over the last few years, but I can't help feeling that I'm missing something obvious, which I've been too dim to spot. Please note the answer to my requirements is *not* a clever use of lattice. This question goes beyond graphs. All suggestions gratefully received! Best wishes, Anthony Staines -- Anthony Staines, Professor of Health Systems Research, School of Nursing, Dublin City University, Dublin 9, Ireland. Tel:- +353 1 7007807. Mobile:- +353 86 606 9713 ______________________________________________ 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.