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rplyrsumifsdplyr

Creating a function to return a column

I need to create a function to return a column given in to the function as an argument. Eg 

fun = function (parameter) {
result = get(paste0("dataframe","parameter"))
return(result) }

so that if I would use fun (columnnamethatexists) it would return dataframe$columnnamethatexists

Currently, what it does is return dataframe$parameter does not exist, no matter what I put in as input.

Sorry for a stupid Q which is probably a replicate, yet I could not find it.

Thanks!

Solution 
  • dataframe <- data.frame(a = 1:10, b = LETTERS[1:10])

fun <- function(val) {
  dataframe[, val]
}

fun("a")
#  [1]  1  2  3  4  5  6  7  8  9 10
fun("b")
#  [1] A B C D E F G H I J
# Levels: A B C D E F G H I J