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: 

```
local list = "nominalprice realprice"
foreach i of local list {
  summarize `i'
  twoway (scatter `i' time)
  graph export "C:\TimePlot-`i'.png"
}

```

This will plot the time series of nominal and real prices and export one graph called TimePlot-nominalprice.png and another called TimePlot-realprice.png. 

In R the method I've come up with to do the same thing would be: 

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

```

This R code looks unintuitive and messy to me and I haven't found a good way to do this sort of thing in R yet. Maybe I'm just not thinking about the problem the right way? Can you suggest a better way to loop using strings?