[R-meta] specified weights in rma

[James Pustejovsky]

Antonia,

The code looks correct to me, and it looks like it is producing the
weighted average just as you specified:

    mean_effect <- weighted.mean(effect, w = weight)
    all.equal(mean_effect, as.numeric(meta$b), check.attributes = FALSE)

Also, note that the output of weights() is re-scaled to sum to 100, which
is why it does not agree with the inputted weights:

    (rma_wt <- weights(meta))
    sum(rma_wt)
    100 * weight / sum(weight)
    all.equal(rma_wt, 100 * weight / sum(weight), check.attributes = FALSE)

Cheers,
James



On Fri, Aug 3, 2018 at 7:10 AM Antonia Sudkaemper <a.sudkaemper using gmail.com>
wrote:

> Hello all,
>
> I am trying to run a meta-analysis with specified weights, but even though
> the code seems right the analysis seems to apply the default weights rather
> than the ones I specify - is there something wrong with the code?
>
> effect = c(2.46, 3.11, 3.93)
> error = c(0.44, 0.38, 0.57)
> weight = c(5.16, 6.70, 3.05)
> study<-c("Study1", "Study2", "Study3")
>
> summary(meta <- rma(yi=effect, sei=error, weights=weight, slab=study))
> weights(meta)
>
>
> Thank you very much for your help.
>
> All the best, Antonia
>
> --
> Antonia Sudkämper
> PhD Candidate in Organizational Psychology/University of Exeter
> www.antoniasudkaemper.com
> a.sudkaemper using gmail.com
>
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