Unpivot multiple group columns in R

Question

I have a data frame which I want unpivot based on group using R. My input is like Input dataframe

userid=c(1,2,3)
GroupA_measure1=c(65,96,12)
GroupA_measure2=c(70,89,14)
GroupB_measure1=c(45,12,38)
GroupB_measure2=c(50,8,40)

Input=data.frame(userid,GroupA_measure1,GroupA_measure2,GroupB_measure1,GroupB_measure2)

userid=c(1,1,2,2,3,3)
measure=c(1,2,1,2,1,2)
GroupA=c(65,70,96,89,12,14)
GroupB=c(45,50,12,8,38,40)

Output=data.frame(userid,measure,GroupA,GroupB)

My expected output is like Output data frame. Please help me out if you have the solution for this

Answer 1

You can do:

library(tidyverse)
Input %>%
  pivot_longer(-userid,
               names_pattern = '(.*)_measure(.)',
               names_to = c('.value', 'measure'))

# A tibble: 6 x 4
  userid measure GroupA GroupB
   <dbl> <chr>    <dbl>  <dbl>
1      1 1           65     45
2      1 2           70     50
3      2 1           96     12
4      2 2           89      8
5      3 1           12     38
6      3 2           14     40