README.md
In setter: Mutators that Work with Pipes

setter: Mutators That Work With Pipes

Mutators to set attributes of variables, that work well in a pipe (much like stats::setNames).

To install the development version, you first need the devtools package.

install.packages("devtools")

Then you can install the setter package using

library(devtools)
install_bitbucket("richierocks/setter")

Functionality

set_* functions change an attribute, then return their first input, allowing you to chain them together. For example, to turn a vector into a matrix, you could do

m <- 1:12 %>%
  set_dim(3:4) %>%
  set_dimnames(list(letters[1:3], LETTERS[1:4])) 
##   A B C  D
## a 1 4 7 10
## b 2 5 8 11
## c 3 6 9 12

To copy attributes from one variable to another, use a copy_* function.

month.abb %>%
  copy_dim(x) %>%
  copy_dimnames(x)
##   A     B     C     D    
## a "Jan" "Apr" "Jul" "Oct"
## b "Feb" "May" "Aug" "Nov"
## c "Mar" "Jun" "Sep" "Dec"

set_* and copy_* functions are available for the following attributes: names, colnames, rownames, dimnames, class, dim, length.

There are also set_attributes and copy_attributes for setting/copying arbitrary attributes. Here's the previous example thrice more. copy_all_attributes and copy_most_attributes provide a shortcut for copying all the outputs, the latter using base::mostattributes<- to take special care with dim, names and dimnames.

month.abb %>%
  copy_attributes(x, c("dim", "dimnames"))
month.abb %>%
  copy_all_attributes(x) 
month.abb %>%
  copy_most_attributes(x) # special care with dim, names, dimnames