[R] Metafor and forest(); not showing 'ilab' and text

[Marco Colagrossi]

Thanks for your help,

I got the mistake I was making and I managed to find a solution
regarding those graphs; I don't want to abuse of your patience but I
have three further questions:

1. Always regarding the forest plots, it is possible to make a
cross-subset? I try to explain my self better; I have one dummy
variable called pub and another variable called SIMiv that can take
the values of "share", "loan", "number" and "duration". How can I
subset my sample so that the forest shows only (for example) studies
when the dummy takes the value of 1 and the SIMiv variable takes the
values of "share" and "loan"?
Something like this:
forest(pc, var, ci95m, ci95p, slab = authoryear2, psize=1,
subset=(pub==1, SIMiv=("share", "loan", "duration"))

2. I have few doubts regarding the multilevel modeling;
    rma.mv(pc, var, random = ~ 1 | author, data=codebook)
   if I'm correct this should be a multilevel model nested at "author"
level; what I cannot understand If it is a varying intercept
(Y=A+BjX), a varying slope (Y=Aj+BX) or a varying intercept&slope
model (Y=Aj+BjX). Are there the formulas for it somewhere? So far I
only found the formulas for the estimators included in the metafor
package.

3. metareg1 <- rma.mv(pc, var, random = ~ 1 | author, mods = ~ pub +
SIMiv, data=codebook)
Again, if I'm correct this should be a multilevel meta regression
(correct me if I'm wrong); I have the same doubts as before.

Thank you again

Marco

On 25 August 2015 at 19:24, Michael Dewey <lists at dewey.myzen.co.uk> wrote:
> Dear Marco
>
> When you change xlim it increases the width of the forest plot in the sense
> you describe. It does not push your text out of the way to make space for it
> but instead overprints it. You may like to use alim to truncate your
> confidence interval whiskers to fit within the space you see or make your
> labels shorter.
>
>
> On 25/08/2015 17:25, Marco Colagrossi wrote:
>>
>> I think I've not explained myself well. When I say "the width of the
>> forest plot" I mean the region above the observed outcome, the
>> "actual" forest plot, not the plot as a whole. Even if I change values
>> for Xlim, cex or ilab.xpos the width of that particular region within
>> the plot doesn't change.
>>
>> Best,
>>
>> Marco
>>
>> On 25 August 2015 at 18:11, Viechtbauer Wolfgang (STAT)
>> <wolfgang.viechtbauer at maastrichtuniversity.nl> wrote:
>>>
>>> The 'xlim' argument does not change the actual width of the plotting
>>> device. For that, you need to use the 'width' argument with whatever device
>>> you are actually using. You can then use the 'xlim' argument to create
>>> appropriate spacing to the left/right of the part of the plot that shows the
>>> estimates and their CIs. Within that space, you can then add additional
>>> columns with the 'ilab' argument. It's up to you to find an appropriate
>>> combination of plotting device width, character/symbol expansion factor
>>> ('cex' argument), 'xlim' values, and 'ilab.xpos' values to create a nice
>>> looking plot that has no overlapping text and no excessive white space. An
>>> example is this:
>>>
>>> http://www.metafor-project.org/doku.php/plots:forest_plot_with_subgroups
>>>
>>> Note that it took me dozens of iterations to create that plot. You just
>>> have to start experimenting.
>>>
>>> Best,
>>> Wolfgang
>>>
>>>> -----Original Message-----
>>>> From: Marco Colagrossi [mailto:marco.colagrossi at gmail.com]
>>>> Sent: Tuesday, August 25, 2015 17:59
>>>> To: Viechtbauer Wolfgang (STAT)
>>>> Cc: r-help at r-project.org; Michael Dewey
>>>> Subject: Re: [R] Metafor and forest(); not showing 'ilab' and text
>>>>
>>>> Thanks again for your help. I'm sorry to bother you but I don't get
>>>> how to widen the forest plot; if I try to change the values of xlim or
>>>> the ilab.xpos values the width of the forest plot region does not
>>>> change, but only moves on the graphs. What I'm I missing?
>>>>
>>>>
>>>> forest(pc, var, ci95m, ci95p, slab = authoryear, psize=1,
>>>> subset=(pub==1),
>>>>         xlim = c(-16, 6),
>>>>         ilab = data.frame(SIMdv, SIMiv),
>>>>         ilab.xpos = c(-7.5, -5.5), cex = 0.75)
>>>> op <- par(cex=.75, font=2)
>>>>        text(c(-7.5, -5.5), 54, c("DV", "IV"))
>>>>        text(-16,                54, "Author(s) and Year",     pos=4)
>>>>        text(6,                  54, "Outcome [95% CI]", pos=2)
>>>> par(op)
>>>>>
>>>>> par("usr")[1:2]
>>>>
>>>> [1] -16   6
>
>
> --
> Michael
> http://www.dewey.myzen.co.uk/home.html