UC Business Analytics R Programming Guide

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Adding Attributes to Vectors

The attributes that you can add to vectors includes names and comments. If we continue with our vector v1 we can see that the vector currently has no attributes:

attributes(v1)
## NULL

We can add names to vectors using two approaches. The first uses names() to assign names to each element of the vector. The second approach is to assign names when creating the vector.

# assigning names to a pre-existing vector
names(v1) <- letters[1:length(v1)]
v1
##  a  b  c  d  e  f  g  h  i  j 
##  8  9 10 11 12 13 14 15 16 17
attributes(v1)
## $names
##  [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j"

# adding names when creating vectors
v2 <- c(name1 = 1, name2 = 2, name3 = 3)
v2
## name1 name2 name3 
##     1     2     3
attributes(v2)
## $names
## [1] "name1" "name2" "name3"

We can also add comments to vectors to act as a note to the user. This does not change how the vector behaves; rather, it simply acts as a form of metadata for the vector.

comment(v1) <- "This is a comment on a vector"
v1
##  a  b  c  d  e  f  g  h  i  j 
##  8  9 10 11 12 13 14 15 16 17
attributes(v1)
## $names
##  [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j"
## 
## $comment
## [1] "This is a comment on a vector"