Rearranging data from tibble into a dataframe in R

I have a tibble in R arranged like this (just the first 20 rows of thousands):

A tibble: 20 × 4

and I want to arrange it to look like this:

…The table goes on for thousands of lines. There can be a varying number of targets for a given TF value. How do I create this second table as a dataframe in R given the first table?

Thank you!

>Solution :

library(dplyr)

df %>% 
  group_by(TF) %>% 
  summarise(Targets = list(target))

#>    TF                                                                        Targets
#> 1 Ahr Cyp1a1, Cyp1a2, Cyp1b1, Fos, Myc, Ugt1a7c, Ugt1a6a, Ugt1a6b, Asap1, Erg, Vgll4
#> 2  Ar              Abce1, Acad12, Acad10, Ahsg, Akr1b3, Akt1, Anapc10, Ap2m1, Appbp2

This results in a so-called list-column (Targets is a list of character vectors), that will work for varying numbers of targets per TF.

With data:

df <- read.table(text =
'TF confidence  target  mor
Ahr B   Cyp1a1  1
Ahr B   Cyp1a2  1
Ahr B   Cyp1b1  1
Ahr B   Fos 1
Ahr B   Myc 1
Ahr B   Ugt1a7c 1
Ahr B   Ugt1a6a 1
Ahr B   Ugt1a6b 1
Ahr B   Asap1   1
Ahr B   Erg 1
Ahr B   Vgll4   1
Ar  A   Abce1   1
Ar  A   Acad12  1
Ar  A   Acad10  1
Ar  A   Ahsg    1
Ar  A   Akr1b3  1
Ar  A   Akt1    1
Ar  A   Anapc10 1
Ar  A   Ap2m1   1
Ar  A   Appbp2  1',
header = TRUE)