Loop over string variables in R

Question

When programming in Stata I often find myself using the loop index in the programming. For example, I\'ll loop over a list of the variables nominalprice and realprice:

Answer 1

If your main issue is the need to type eval(parse(text=i)) instead of ``i'`, you could create a simpler-to-use functions for evaluating expressions from strings:

e = function(expr) eval(parse(text=expr))

Then the R example could be simplified to:

clist <- c("nominalprice", "realprice")
for (i in clist) {
  png(paste("c:/TimePlot-", i, ".png", sep=""))
  plot(time, e(i))
  dev.off() 
}