Modify variable names and variables within R function

Question

I have some variables var1, var2, ..., var100

I would like to create new variables var1_trun, var2_trun, ..., var100_trun

which should have the same values as var1, var2, ..., var100 except the values above the 90%-percentile. Those values should be set equal to the 90%-percentile of the original vairables.

What is the best way to accomplish this?

I tried:

 trun <- function(x) {

 assign(paste0(substitute(x),"_trun"))<<-x
 assign(paste0(substitute(x),"_trun"))[x>quantile(x, probs=seq(0,1,0.05))[19]]<<-quantile(x, probs=seq(0,1,0.05))[19]
  }

 trun(data$var1)

I get:

Error in assign(paste0(substitute(x), "_trun")) <<- x : 
  object 'x' not found.

Answer 1

This is really the wrong approach. Don’t create variables named like this (and, just to clarify: what you actually call them is relatively unimportant; what’s important is that you have data of the same general shape — this data belongs grouped into a homogeneous container). Maintain one variable that’s a list, a vector or a matrix (depending on your data).

This will vastly simplify your code.

That said, your code has a very straightforward error: instead of assign(…) <<- x, you need to do assign(…, x), and specify the target environment. So, in your case:

assign(paste(substitute(x), "trun", sep = "_"), x, envir = parent.frame())