Displaying 1 result from an estimated 1 matches for "twin1".
Did you mean:
twine
2007 Oct 11
1
constraining correlations
...er family plus up to 2 siblings. I would like to
somehow constrain all the sibling correlations (twin-sib and sib-sib)
to be the same while allowing the twin-twin correlation to be
different. Here is some simulated code:
set.seed(5)
famdata <- matrix(rnorm(400),ncol=4,dimnames=list(NULL,c("Twin1","Twin2","Sib1","Sib2")))
famdata[runif(100)<.2,3] <- NA #20% of sib 1s are missing
famdata[runif(100)<.4,4] <- NA #40% of sib 2s are missing
cor(famdata,use="pairwise.complete")
<R output>
Twin1 Twin2 Sib1...