Show mapping of factor levels and factor values in R

Question

I'm wondering if there's any function to show the mapping of levels and values of a factor variable in R? For example I would expect an output like this:

Fac_level: "yes" - Value: "1",

Fac_level: "no" - Value: "2", etc.

That would be very helpful while working with unknown data sets for the first time.

Answer 1

How about this:

x <- factor(sample(LETTERS[1:10], 20, TRUE))
> x
# [1] I I I H D E I H F D J G D A F F B H I F
#Levels: A B D E F G H I J

data.frame(levels = unique(x), value = as.numeric(unique(x)))
#  levels value
#1      I     8
#2      H     7
#3      D     3
#4      E     4
#5      F     5
#6      J     9
#7      G     6
#8      A     1
#9      B     2