rparsingdplyraggregategrouped-table

Rename column in grouped tibble by row value (dplyr)

How can I rename a column within a grouped dplyr tibble, depending on a certain row value? The following graphic shows how my tibble looks before and how it should be looking after the manipulation.

enter image description here

I have tried the following code, but did not manage to write a column rename function that is able to state the new column name flexibly from the "name" column.

library(dplyr)

df <- data.frame(
 "splitvar"=c(1,1,1,2,2,3,3,3,3),
 "value"=c(1,4,2,5,6,9,11,13,12),
 "name"=c("Harold","Harold","Harold","Jane","Jane","George","George","George","George"),
 stringsAsFactors=F
)

grouped_tbl <- df %>%
  group_by( splitvar ) %>%
  eval(parse(
    paste0("rename(",unique(name)," = value)")
  ))

Related: Replacement for "rename" in dplyr

Solution

  • Like this: 

    library(tidyverse)

df %>% 
  split(.$splitvar) %>% 
  map(~rename(., !!unique(.$name) := "value"))

    It took some time getting my head around the quosure-thing, but try and take a look at programming with dplyr

    The output of the code is:

    $`1`
  splitvar Harold   name
1        1      1 Harold
2        1      4 Harold
3        1      2 Harold

$`2`
  splitvar Jane name
4        2    5 Jane
5        2    6 Jane

$`3`
  splitvar George   name
6        3      9 George
7        3     11 George
8        3     13 George
9        3     12 George