Object not found error with ddply inside a function

Question

This has really challenged my ability to debug R code.

I want to use ddply() to apply the same functions to different columns that are sequentially nam

Answer 1

You can do this with a combination of do.call and call to construct the call in an environment where NewColName is still visible:

myFunction <- function(x,y){
NewColName <- "a"
z <- do.call("ddply",list(x, y, summarize, Ave = call("mean",as.symbol(NewColName),na.rm=TRUE)))
return(z)
}

myFunction(d.f,sv)
  b Ave
1 0 1.5
2 1 3.5