[SOLVED] How to append a specific string to rows based on column names with dplyr

How to append a specific string to rows based on column names with dplyr

I've got a dataframe containing features of mushrooms, as such:

SPECIES CAP.SHAPE CAP.SURFACE CAP.COLOR BRUISES    ODOR GILL.ATTACHMENT GILL.SPACING GILL.SIZE GILL.COLOR
1  PUNGENTIA    CONVEX       SCALY     BROWN     YES PUNGENT            FREE        CLOSE    NARROW      BLACK
2  YELLOWCAP    CONVEX       SCALY    YELLOW     YES  ALMOND            FREE        CLOSE     BROAD      BLACK
3 BELLSHROOM      BELL       SCALY     WHITE     YES   ANISE            FREE        CLOSE     BROAD      BROWN
  STALK.SHAPE STALK.ROOT STALK.SURFACE STALK.COLOR VEIL.COLOR RING.NUMBER RING.TYPE SPORE.PRINT.COLOR POPULATION
1   ENLARGING      EQUAL        SMOOTH      PURPLE      WHITE         ONE   PENDANT             BLACK  SCATTERED
2   ENLARGING       CLUB        SMOOTH      PURPLE      WHITE         ONE   PENDANT             BROWN   NUMEROUS
3   ENLARGING       CLUB        SMOOTH      PURPLE      WHITE         ONE   PENDANT             BROWN   NUMEROUS
  HABITAT
1   URBAN
2 GRASSES
3 MEADOWS

I want to append a string to the entries of the columns relating to CAP, GILL and STALK, so that their first entries become CONVEX.CAP, SCALY.CAP, BROWN.CAP for the CAP columns, FREE.GILLS, CLOSE.GILLS, NARROW.GILLS, for the GILL columns and so on. I tried to do so with the dplyr package, and by using paste, like so:

reformatted_mushrooms <- mushrooms %>%
  mutate_at(.vars = c("CAP.SHAPE", "CAP.SURFACE", "CAP.COLOR"), .funs = 
              paste("CAP", sep = "."))

This however returns this error:

Error in get(.x, .env, mode = "function") : 
  object 'CAP' of mode 'function' was not found

I also tried using the contains() function, like this:

reformatted_mushrooms <- mushrooms %>%
  mutate_at(.vars = contains("CAP"), .funs = paste("CAP"), sep = ".")

But this yields the following error:

Error: No tidyselect variables were registered

Does anyone see what I'm doing wrong here? Much appreciated.

Solution

Please make shure you provide a reproducible example in your question! Otherwise, you'll create unnecessary effort.

library(tidyverse)

tibble::tibble('CAP.SHAPE' = c(1:5),
               'RANDOM.SHAPE' = c(11:15)) %>%
  mutate_at(vars(contains("CAP")), ~ paste0(.x, ".CAP"))

 A tibble: 5 x 2
  CAP.SHAPE RANDOM.SHAPE
  <chr>            <int>
1 1.CAP               11
2 2.CAP               12
3 3.CAP               13
4 4.CAP               14
5 5.CAP               15