Turn a data frame column into vector with names as row names

Question

I have an output which looks like the following code:

data.frame(H = c(1.5,4.5,5,8)) %>% `rownames<-`(c("a","b","c","d"))
    H
a 1.5
b 4.5
c 5.0
d 8.0

Ideally, using dplyr, I would like to convert it to a vector like this:

  a   b   c   d 
1.5 4.5 5.0 8.0 

Is there anyway I can do this without defining any new variables and using only the pipe operator? Using unlist will not result in the desired outcome.

data.frame(H = c(1.5,4.5,5,8)) %>% `rownames<-`(c("a","b","c","d")) %>% unlist()

    H1  H2  H3  H4 
    1.5 4.5 5.0 8.0

Answer 1

With rownames_to_column + deframe from tibble:

library(tibble)
df %>% 
  rownames_to_column() %>% 
  deframe()

#  a   b   c   d 
#1.5 4.5 5.0 8.0 

Another option with pull

library(dplyr)
library(tibble)
df %>% 
  rownames_to_column() %>% 
  pull(H, rowname)

Or with the exposition pipe %$%:

library(magrittr)
df %$% 
  set_names(H, rownames(.))

---

For the sake of completeness, the base R one-liner:

setNames(df$H, rownames(df))

That can also be piped, with magrittr's %$%:

df %$% 
  setNames(H, rownames(.))

---

Data:

df <- data.frame(H = c(1.5,4.5,5,8)) %>% 
  `rownames<-`(c("a","b","c","d"))