Creating a variable for a phenotype in each twin

I was reviewing the Day 1 script and noticed the variables, WT_T1, and WT_T2 describing the weight for twin 1 and twin 2. I am currently working with a dataset that does not include pre-calculated T1 and T2 variables for the phenotype I am interested in. I am unable to figure out the code for how to create these variables. The goal is to run an ACE model once those variables are created. Thank you!

@Elizabeth_Prom-Worml

Hi @pascaleac ! Take a look here for some code
https://ibg.colorado.edu/cdrom2021/Day00/Working%20with%20Twin%20Data%20in%20R/

and the video to go with it (refer to the video “Working with Twin Data in R”)

Let me know if you have additional questions or concerns.