search for: vijv1

Displaying 20 results from an estimated 27 matches for "vijv1".

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2012 Sep 26
3
Broken Links on http://www.r-project.org
...t/new URL should be: http://www.commanster.eu/rcode.html 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
2013 Sep 15
1
FOSS licence with BuildVignettes: false
...f they have an FOSS license at some point in the future? 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
2024 Oct 11
1
Error message when calling t.test() and aov() with a factor variables
...f the silly things users may do is of course impossible, but for this one adding a check that the (response) variable is actually numeric could be useful. Best, Wolfgang -- Wolfgang Viechtbauer, PhD, Statistician | Department of Psychiatry and Neuropsychology | Maastricht University | PO Box 616 (VIJV1) | 6200 MD Maastricht, The Netherlands | +31(43)3884170 | https://www.wvbauer.com
2017 Jun 22
1
Compiling R-devel - missing some expected features (zlib, bzlib, lzma, PCRE)
...3:amd64 2:8.38-3.1 ii libpcrecpp0v5:amd64 2:8.38-3.1 Any suggestions on what else I may need? Best, Wolfgang -- Wolfgang Viechtbauer, Ph.D., Statistician | Department of Psychiatry and Neuropsychology | Maastricht University | P.O. Box 616 (VIJV1) | 6200 MD Maastricht, The Netherlands | +31 (43) 388-4170 | http://www.wvbauer.com
2013 Dec 12
1
refline in forest() {metafor}
Hello all, I am using forest.rma to plot a random effects model meta-analysis. I noticed that refline sets a vertical line indicating the null hypothesis. Is there a way to draw another vertical line, possibly dashed, centered on the summary estimate? Prof. Viechtbauer, if you happen to read this, I'd like to thank you for making an excellent package. I have been using the metafor package
2012 Aug 01
1
"metafor" package, proportions: single groups wrt to a categorical dependent variable‏
...er variable that confound any difference you may find. 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: Dushanthi Pinnaduwage [mailto:dushanthi at bell.net] > Sent: Tuesday, July 31, 2012 16:40 > To: wvb at metafor-project.org; Dushanthi Pinnaduwage > Subject:...
2012 Jan 14
1
metafor: weights computation in Mantel-Haenszel method
Dear R users, In metafor 1.6-0, the Mantel-Haenszel method is implemented by the rma.mh() function. I have observed that the sum of the weights computed by weights(x) doesn't add to 100% when x is an object of class rma.mh. The consequences of this fact can be clearly seen when a forest diagram is drawn with forest(x), which calls weights(x) (or more precisely, the method weights.rma.mh()
2013 Mar 02
1
Metafor "SMCR" Pre-Post Effect sizes
Dear all, I am very grateful that Wolfgang Viechtbauer implemented the standardised mean change for dependent groups. I was playing around a bit today, and I am not sure if I understand the "SMCR" procedure correctly. The documentation states that sd1i and sd2i are needed, but it seems to me that SMCR is ignoring sd2i (so Variances are not pooled). Instead, it uses sd1i (pre-test sd),
2012 Nov 19
1
Help: Meta-analysis with metacor
Trying to do a meta-analysis of correlations in R using the meta package; have tried several things and keep getting a similar error. Can anyone help explain the error? > cor<-c(-0.3018, 0.667, -3.8002, -0.607, -0.4885, -3.8002, -0.0701, 0.1348, -0.9505, -0.5709, -0.6127, -1.2419, -0.1511, -0.1054)> n<-c(3,4,3,3,3,3,16,36,30,9,3,3,30,4)> library(meta)> metacor(cor, n, data=NULL,
2012 Oct 10
1
combine unadjusted and adjusted forest plots
Hello, I am learning to use the metafor package to conduct meta-regression analyses for a systematic review on multidisciplinary care interventions in chronic kidney disease. For the forest plots, I can't figure out how to plot unadjusted and adjusted models on the same plot. From top to bottom, I would like to be able have the unadjusted plot, the multivariate adjusted plot, then each
2012 Sep 27
1
What to use for ti in back-transforming summary statistics from F-T double square-root transformation in 'metafor'
Hi Dr. Viechtbauer, I'm doing meta-analysis using your package 'metafor'. I used the 'IRFT' to transform the incident rate. But when I tried to back-transform the summary estimates from function rma, I don't know what's the appropriate ti to feed in function transf.iirft. I searched and found your post about using harmonic mean for ni to back-transform the double
2024 Oct 11
1
Error message when calling t.test() and aov() with a factor variables
...eful. Indeed. As always, the question is whether we want to give an error unless is.numeric, or ensure via as.numeric? Best -k > Best, > Wolfgang > -- > Wolfgang Viechtbauer, PhD, Statistician | Department of Psychiatry and > Neuropsychology | Maastricht University | PO Box 616 (VIJV1) | 6200 MD > Maastricht, The Netherlands | +31(43)3884170 | https://www.wvbauer.com > ______________________________________________ > R-devel at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel
2012 May 24
1
package metafor: specify weights?
Dear R-experts, Dear Wolfgang, Weighted model fitting in metafor uses the inverse of the study specific variances as weights. I am wondering if it is possible to specify different weights. In my meta-analysis, there are two types of studies with (intrinsic) differences in their range of sample sizes (which are used to calculate the variances of Fisher's z). I would like to try normalizing
2013 Jun 02
4
Strange behaviour of R graphics copied to PowerPoint
Hello, I am using R to create graphics, especially to plot time series charts. These charts are then copied as metafiles (for best quality) to a PowerPoint presentation and then saved to PDF (via the "Save As" dialog"). Attached is two pictures. The first picture shows how my chart looks like in the R Graphics window, and the second picture shows how the chart becomes after saving
2012 May 05
3
metafor
Dear users of metafor, I am working on a meta-analysis using the metafor package. I have a excel csv database that I am working with. I am interested in pooling the effect measures for a particular subgroup (European women) in this csv database. I am conducting both sub-group and meta-regression. In subgroup-analyses, I have stratified the database to create a separate csv file just for European
2013 Mar 19
1
Error when adding lines to a plot using the mixed-effect model and metafor package
Hi, I am a student using R for my final year project, with the metafor package being particularly helpful. I have been following the steps laid out in the manual 'Conducting Meta-analysis in R with the Metafor package' (Viechtbauer, 2010) and applying it to my own data of infected Anopheles mosquitoes across Africa. In particular, I am attempting to apply a mixed-effect model to my data
2012 Aug 09
1
Factor moderators in metafor
I'm puzzled by the behaviour of factors in rma models, see example and comments below. I'm sure there's a simple explanation but can't see it... Thanks for any input John Hodgson ------------------------------------- code/selected output ----------------- library(metafor) ## Set up data (from Lenters et al A Meta-analysis of Asbestos and Lung Cancer... ##
2012 Jul 24
1
Annotate forest plot 'forest.rma()' for meta-analysis with metafor package
Dear R-experts, The forest.rma() function from the metafor package creates nice forest plots for presenting the results of a meta-analysis. These plots can be annotated for e.g. giving names to the columns. E.g. as in the documentation of the package: data(dat.bcg) ### meta-analysis of the log relative risks using a random-effects model res <- rma(ai=tpos, bi=tneg, ci=cpos, di=cneg,
2012 Aug 22
1
(Slight) calculation discrepancy in escalc (metafor package)
Hello, I recently started using the metafor package (version 1.6-0) in R (2.15.1, 64-bit Windows 7) and noticed that I was getting slightly different values when I manually calculated the standardized mean difference versus what escalc was giving me. Here''s a very simple example: escalc(measure="SMD", m1i=5,m2i=10,n1i=5,n2i=5,sd1i=1,sd2i=2,vtype="LS") The result
2012 Sep 11
1
using alternative models in glmulti
All, I am working on a multiple-regression meta-analysis and have too many alternative models to fit by hand. I am using the "metafor" package in R, which generates AIC scores among other metrics. I'm using a simple formula to define these models. For example, rma(Effect_size,variance, mods=~Myco_type + N.type +total, method="ML")->mod where Effect_size is the