I know the question has probably already been asked, but I couldn't find instances of the specific problem I'm facing with melting at the presence of multiple measure vars. I have a data table like this.
library(data.table)
set.seed(234)
DT<-data.table(item=1:3,phase=c("pre-test","test","follow up"),
control_RT=sample(400:600,3),control_ecc=sample(100:200,3),
oa_RT=sample(500:700,3),oa_ecc=sample(200:250,3),ya_RT=sample(450:550,3),ya_ecc=sample(230:260,3))
All I need to do is to put the variables RT and ecc in two separate columns by category, and add a column in which the category is specified:
item phase RT ecc Category
1 pre-test 549 178 control
2 test 556 106 control
3 follow up 403 163 control
1 pre-test 686 214 oa
2 test 643 227 oa
3 follow up 684 226 oa
1 pre-test 508 243 ya
2 test 550 239 ya
3 follow up 450 251 ya
I tried to use reshape with varying function but had no success. Any advice?