[R] metafor escalc(measure="SMCC")

[Viechtbauer Wolfgang (STAT)]

.cmicalc is a non-exported function. You can see the code with:

getAnywhere(.cmicalc)

Best,
Wolfgang

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
> On Behalf Of petretta at unina.it
> Sent: Thursday, November 21, 2013 13:39
> To: r-help at r-project.org
> Subject: [R] metafor escalc(measure="SMCC")
> 
> Many thanks to Wolfgang Viechtbauer for the prompt and clear answer.
> However, I'm unable to understand what .cmicalc mathematically does in the
> code line:
> 
> cmi <- .cmicalc(mi)
> 
> I look in the metafor documentation and in R (?.cmical and ??.cmicalc) but
> I have no result. Please, can I have further explanation on this point?
> 
> Sorry for the trouble
> 
> Sincerely
> 
> Mario Petretta
> Department of Translational Medical Sciences
> Naples University Federico II
> Italy
> 
> >
> Message: 50
> Date: Tue, 19 Nov 2013 11:48:33 +0100
> From: "Viechtbauer Wolfgang (STAT)"
>         <wolfgang.viechtbauer at maastrichtuniversity.nl>
> To: "petretta at unina.it" <petretta at unina.it>, "r-help at r-project.org"
>         <r-help at r-project.org>
> Subject: Re: [R] metafor escalc(measure="SMCC")
> Message-ID:
>         <077E31A57DA26E46AB0D493C9966AC730D9925568A at UM-
> MAIL4112.unimaas.nl>
> Content-Type: text/plain; charset="us-ascii"
> 
> Dear Mario,
> 
> You can always just inspect the code:
> 
> escalc.default
> 
> Best,
> Wolfgang
> 
> --
> Wolfgang Viechtbauer, Ph.D., Statistician
> Department of Psychiatry and Psychology
> School for Mental Health and Neuroscience
> Faculty of Health, Medicine, and Life Sciences
> Maastricht University, P.O. Box 616 (VIJV1)
> 6200 MD Maastricht, The Netherlands
> +31 (43) 388-4170 | http://www.wvbauer.com
> 
> > -----Original Message-----
> > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
> > On Behalf Of petretta at unina.it
> > Sent: Tuesday, November 19, 2013 11:29
> > To: r-help at r-project.org
> > Subject: [R] metafor escalc(measure="SMCC")
> >
> > Dear all,
> >
> > I use R 3.0 for Windows.
> >
> > I ask how escalc(measure="SMCC") [metafor package] mathematically
> > calculate yi and vi when only change score and SD change score are
> > provided.
> >
> > I used the example (repoted below) posted by Qiang Yue at:
> >
> > http://r.789695.n4.nabble.com/using-metafor-for-meta-analysis-of-before-
> > after-studies-escalc-SMCC-td4667233.html
> >
> > but it is unclear for me the formula used to derive y1 and v1. I read
> > the documentation of metafor package and it is all very well
> > described, but I ask if possible for the formula used by
> > escalc(measure="SMCC") to mathematically calculate yi and vi.
> > Unfortunatel, I have no free access to the paper quoted in metafor
> > package.
> >
> > Beginning example:
> >
> > fMRS
> > author year n mean_r sd_r mean_s sd_s r
> > 1 Tom  2006 9  0   0 0.12 0.03    0   0
> > 2 Jack 2012 6  0   0 0.23 0.05    0   0
> > 3 Zhu  2013 8  0   0 0.18 0.05    0   0
> >
> > >
> >
> dat_SMCC=escalc(measure="SMCC",data=fMRS,ni=n,m1i=mean_s,m2i=mean_r,sd1i=s
> > d_s,sd2i=sd_r,ri=r
> > ,append=TRUE)
> > > dat_SMCC
> > author year n mean_r sd_r mean_s sd_s r  yi      vi
> > 1 Tom 2006  9  0     0    0.12  0.03  0 3.6108 0.8354
> > 2 Jack 2012 6  0     0    0.23  0.05  0 3.8674 1.4131
> > 3 Zhu 2013  8  0     0    0.18  0.05  0 3.1975 0.7640
> >
> >
> >
> > Sincerely
> >
> > --
> > Mario Petretta
> > Department of Translational Medical Sciences
> > Naples University Federico II
> > Italy
> >
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.