Here are a few suggestions:
Assert that the model converged each time, e.g., by adding something
like -assert e(converged)==1- as a command after -xtmixed-. -assert-
is your friend. Add the permute option seed(#) or -set seed #- before
calling -permute-, for replication purposes. Run again and examine the
output. If you need more detailed info, -set trace on-, run again and
examine why Stata complains. Does that help? Can you replicate the
problem using a Stata-provided dataset?
Anders Alexandersson
[email protected]
Fotios Drenos <[email protected]> wrote:
> I am trying to run a permutation tests on an xtmixed command and the
> I get a convergence error.
>
> The command I am using is:
>
> program test5, rclass
> version 9
> args dependent fac_gene fac_measurement
> xi: xtmixed `dependent' i.`fac_gene' `fac_measurement'||sno:
> `fac_measurement', cov(unstruct)
> testparm _I`fac_gene'*
> return scalar pgene=r(p)
> end
>
>
> permute sqrtchol t=r(pgene), reps(100) noi : test5 sqrtchol gv242 visit
>
> Any suggestions of what goes wrong here?
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