Hi Mike,
Thanks very much for your excellent metaSEM package. I have successfully wrangled my data into the necessary format and run a fixed effect model and then a random effects model with the "diag" option. The data is 37 samples (ranging in size from 28 to 1589) of 8 variables (and none of the samples have missing data; all samples provide all 28 correlations). I can't get the random effects model to run with the "Symm" option, and it is driving me nuts as to why this is the case. I get Open Mx error code 6, and all of the parameters come out NA.
As a second question, I was wondering if you had any resources on the similarities and differences between metaSEM's tssem1() and metafor's rma.mv (the multivariate meta-analysis). I've been trying to compare and contrast results in both programs, and I'm not sure I'm giving either program the proper inputs. They are running, and giving somewhat similar results (typically +/- .02 correlation units), which makes me feel like I'm on the right track.
Thank you!
Katie
P.S. As a side note - I was trying to run analyses in metaSEM on my mac running OS 10.8.5, and I couldn't get any commands to run (I got a cryptic c++ error). After switching to my laptop running OS 10.9.5, everything seems to work OK (except the aforementioned REM).
Hi Katie,
The first question is related to the number of parameters. Since there are 8 variables, there are 87/2=28 correlation coefficients. There will be 2829/2=406 elements in the variance component of the random effects. Thirty-seven samples do not seem to be enough to estimate all parameters.
The mathematical models between tssem1() and metafor's rma.mv() are the same. Both of them are standard multivariate meta-analysis. tssem1() uses ML estimation. If you are also using ML estimation in rma.mv(), the results should be the same.
Regarding the Mac issue, I am sorry that I rarely use Mac. Maybe other Mac users may comment on whether this is due to Mac's version or other issues.
Mike