I have a data frame like this a
x <- data.frame("Name" = c("John","Dora"),"SN" = 1:2,"SN_1" = 7:8,"SN_2" = 5:6 )
Name SN SN_1 SN_2
1 John 1 7 5
2 Dora 2 8 6
And I want to transform it to:
Name SN
1 John 1
2 Dora 2
3 John 7
4 Dora 8
5 John 5
6 Dora 6