[R-meta] mods~factor

[Viechtbauer, Wolfgang (SP)]

It should be: mods = ~ field

Best,
Wolfgang

>-----Original Message-----
>From: angelo solarino [mailto:angelosolarino using gmail.com]
>Sent: Tuesday, 29 June, 2021 20:14
>To: Viechtbauer, Wolfgang (SP)
>Cc: r-sig-meta-analysis using r-project.org
>Subject: Re: [R-meta] mods~factor
>
>Wolfgang,
>
>thanks again for your time.
>when running the metaregression with a categorical variable (field) I should see
>the levels of the variable in the regression output with the following labels:
>Etrep; Finance, IB, and Manag.
>
>the code used:
>
>> res <- rma(yi,vi, mods ~ field, data=cells, method = "HS")
>> res
>
>Random-Effects Model (k = 122; tau^2 estimator: HS)
>
>tau^2 (estimated amount of total heterogeneity): 0.0037 (SE = 0.0010)
>tau (square root of estimated tau^2 value):      0.0612
>I^2 (total heterogeneity / total variability):   87.69%
>H^2 (total variability / sampling variability):  8.12
>
>Test for Heterogeneity:
>Q(df = 121) = 1015.5701, p-val < .0001
>
>Model Results:
>
>estimate      se    zval    pval    ci.lb   ci.ub
>  0.0025  0.0065  0.3821  0.7024  -0.0103  0.0153
>
>---
>Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
>
>the examples work just fine, with other datasets , it works as well.
>so I'm trying to understand what is different here and why I am getting neither
>the expected results nor an error message.
>
>any hint is welcome!
>Thanks again,
>
>Angelo
>
>Il giorno mar 29 giu 2021 alle ore 16:15 Viechtbauer, Wolfgang (SP)
><wolfgang.viechtbauer using maastrichtuniversity.nl> ha scritto:
>Please always cc the mailing list when responding.
>
>You haven't actually stated what the problem is. What exactly do you mean by "I
>can't get the factors in the metaregression"? What error do you get? Or what is
>the output that you get that is not in accordance with what you were expecting?
>
>Best,
>Wolfgang
>
>>-----Original Message-----
>>From: angelo solarino [mailto:angelosolarino using gmail.com]
>>Sent: Tuesday, 29 June, 2021 17:03
>>To: Viechtbauer, Wolfgang (SP)
>>Subject: Re: [R-meta] mods~factor
>>
>>Dear Wolfgan,
>>
>>thank you for your quick reply.
>>
>>Unfortunately, I still can't get the factors in the metaregression. In other
>>projects with metafor, it never encountered this issue before, so i am not
>certain
>>what is causing it.
>>
>>I have re-started the project in a new space after having updated R, Rtools, and
>>metafor to the most recent versions. The issue persists.
>>Have you ever encountered this issue before? all the other parts works, it just
>>the meta regressions that is causing some troubles.
>>
>>Thanks a lot for having developed such a great tool, and let me know if you have
>>any advice on how to overcome this problem.
>>All the best,
>>Angelo
>>
>>Il giorno mar 29 giu 2021 alle ore 12:10 Viechtbauer, Wolfgang (SP)
>><wolfgang.viechtbauer using maastrichtuniversity.nl> ha scritto:
>>Dear Angelo,
>>
>>The factor() function is not something from metafor, but is part of R itself.
>>
>>String variables are automatically converted to factors, so using factor() on
>them
>>doesn't change anything.
>>
>>As for the interpretation of results when including factor variables in models,
>>see:
>>
>>https://www.metafor-project.org/doku.php/tips:models_with_or_without_intercept
>>
>>Best,
>>Wolfgang
>>
>>>-----Original Message-----
>>>From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces using r-project.org] On
>>>Behalf Of angelo solarino
>>>Sent: Tuesday, 29 June, 2021 12:21
>>>To: r-sig-meta-analysis using r-project.org
>>>Subject: [R-meta] mods~factor
>>>
>>>DA,
>>>
>>>I am having some trouble with the "factor" command in metafor.
>>>I am not able to get the split for the variable field. it is a string
>>>value. whether i add "mods~factor(field)"  or not I get the same main
>>>effect results, and there is no error message. Can anyone help me figure
>>>out what I am doing wrong?
>>>
>>>res <- rma(yi,vi, mods~factor(field), data=Outcomes1, method = "HS",
>>>subset=(ID=="XX" | ID=="XY"))
>>>
>>>Thanks a lot for your help,
>>>Angelo