I can´t answer your question in the comments due to low reputation score.
The next code will give you an error because the paste function return a character string
for(i in 1:length(var.out)) {
paste("data$", var.out[i], sep="") <- NULL
}
Here is a possible solution:
for(i in 1:length(var.out)) {
text_to_source <- paste0 ("data$", var.out[i], "<- NULL") # Write a line of your
# code like a character string
eval (parse (text=text_to_source)) # Source a text that contains a code
}
or just do:
for(i in 1:length(var.out)) {
data[var.out[i]] <- NULL
}