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

[Viechtbauer, Wolfgang (SP)]

Dear Danka,

The "Error in plot.new() : figure margins too large" message has nothing to do with metafor. I would guess you are using Rstudio and the plotting pane is too small.

As for the rest, it's difficult to say what is going on. To start, make sure you first install the 'devel' version of metafor:

https://wviechtb.github.io/metafor/#installation

Maybe that already takes care of some of these issues. Could you also post the command you used to fit model 'es.re.mv' and the output from that model?

Best,
Wolfgang

-----Original Message-----
From: Danka Puric [mailto:djaguard using gmail.com] 
Sent: Tuesday, 07 May, 2019 19:38
To: Viechtbauer, Wolfgang (SP)
Cc: r-sig-meta-analysis using r-project.org
Subject: Re: [R-meta] stepadj argument ignored in an rma.mv model

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