[R-meta] stepadj argument ignored in an rma.mv model

[Danka Puric]

Dear Wolfgang,

Thank you so much for this quick reply! I needed to do some reading before
I could respond. I'm quite new to nested models, so I'm still trying to
wrap my head around them.

I tried changing the optimizer to BFGS and Nelder-Mead and the latter
resulted in model convergence (the former didn't). Problem solved! Well,
partly - some of the variance component estimates in the model, namely
sigma2 and gamma2, are zero.

Moreover, when I run profile() on this model I'm getting the following
message:
Profiling sigma2 = 1
 |==========================================================================================|
100%
Error in plot.new() : figure margins too large
In addition: Warning messages:
1: In min(x) : no non-missing arguments to min; returning Inf
2: In max(x) : no non-missing arguments to max; returning -Inf

When I tried plotting just over tau2 and rho (like in the example on the
profile.rma.mv help page), I got similar messages:
> profile(es.re.mv, tau2=1)
|==========================================================================================|
100%
Error in plot.window(...) : need finite 'ylim' values
In addition: Warning messages:
1: In min(x) : no non-missing arguments to min; returning Inf
2: In max(x) : no non-missing arguments to max; returning -Inf
> profile(es.re.mv, tau2=2)
Error in profile.rma.mv(es.re.mv, tau2 = 2) :
  No such 'tau2' component in the model.
> profile(es.re.mv, rho=1, xlim=c(.90, .98))
 |==========================================================================================|
100%
Error in plot.window(...) : need finite 'ylim' values
In addition: Warning messages:
1: In min(x) : no non-missing arguments to min; returning Inf
2: In max(x) : no non-missing arguments to max; returning -Inf

I would assume that this means (at least some of) the variance components
are actually not identified. Is that the case? And does that mean that I
should probably try fitting a different model?

Thanks a lot for your help!
Best,
Danka

On Tue, May 7, 2019 at 8:08 AM Viechtbauer, Wolfgang (SP) <
wolfgang.viechtbauer using maastrichtuniversity.nl> wrote:

> Dear Danka,
>
> rma.uni() and rma.mv() use different optimization routines. The link you
> sent mostly pertains to rma.uni(). For one thing, the optimizers used in
> rma.mv() do not have a 'stepadj' control argument (which is also what the
> warning message is telling you).
>
> If you run into convergence problems with rma.mv(), first take a look at
> help(rma.mv) and the "Note" section towards the end. One of the first
> things you can try is to switch to 'optim' for the optimizer and then use
> either the 'BFGS' or 'Nelder-Mead' methods. So:
>
> control=list(optimizer="optim", optmethod="BFGS")
>
> or
>
> control=list(optimizer="optim", optmethod="Nelder-Mead")
>
> Maybe that already fixes things. If so, please also run profile() on the
> fitted model to make sure that all variance components are clearly
> identiable. See help(profile.rma.mv).
>
> Best,
> Wolfgang
>
> -----Original Message-----
> From: R-sig-meta-analysis [mailto:
> r-sig-meta-analysis-bounces using r-project.org] On Behalf Of Danka Puric
> Sent: Monday, 06 May, 2019 12:28
> To: r-sig-meta-analysis using r-project.org
> Subject: [R-meta] stepadj argument ignored in an rma.mv model
>
> Hi everyone!
>
> I'm running a meta-analysis using the rma.mv function and have run into
> some issues with the stepadj argument.
>
> One of the models I'm testing won't converge, with the following message:
> Error in rma.mv(ES_corrected, SV, random = list(~1 | MA_data$IDeffect,  :
>   Optimizer (nlminb) did not achieve convergence (convergence = 1).
>
> Following the advice on this page:
>
> http://www.metafor-project.org/doku.php/tips:convergence_problems_rma?s[]=convergence
> I tried increasing the number of iterations (up to maxiter = 10000), but
> the model wouldn't converge. I then tried shortening the step length to
> stepadj = 0.5. The model still failed to converge, but I also got the
> following message:
> Warning message:
> In nlminb(start = c(con$sigma2.init, con$tau2.init, con$rho.init,  :
>   unrecognized control elements named ‘stepadj’ ignored
>
> I get the same message when I try to adjust step length for models that do
> converge, so I'm hopeful that this model would also converge if only I
> could get the stepadj to work.
>
> Has anyone else had this issue when using stepadj with the rma.mv
> function?
> Any input would be greatly appreciated. Thank you in advance!
>
> Best,
> Danka
>

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