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Wolfgang Viechtbauer

@wviechtb.bsky.social

Assoc Prof of Methodology and Statistics at Maastricht University. Interests: meta-analysis, ESM/EMA, mixed-effects models, computational statistics, research software, R, FLOSS, GNU/Linux, chess, piano, lolcats. The views expressed are those of my cats.

400 Followers  |  415 Following  |  57 Posts  |  Joined: 28.01.2025
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Posts by Wolfgang Viechtbauer (@wviechtb.bsky.social)

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Bifurcation diagram for the logistic map Bifurcation diagram for the logistic map. GitHub Gist: instantly share code, notes, and snippets.

Since this is an #Rstats post ... R code to create a bifurcation diagram for the logistic map here: gist.github.com/wviechtb/f49...

05.03.2026 13:59 β€” πŸ‘ 3    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Exactly. Same for me under full 4k resolution, which is crazy. I assume you are also using 200% scaling. Go to Properties for RGui, Compatibility, Change high DPI settings, High DPI scaling override, Application, and then try dev.size("px") again. Should be 2x.

25.02.2026 20:55 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

That's also what I initially thought, but it's not that. What do you get when you open Rgui and run dev.size("px")?

25.02.2026 15:47 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

I rarely use Windows, but noticed that #Rstats plots under Windows (using windows()) looked very fuzzy even with a 4k resolution. This seems to be related to DPI scaling (the system was using 200%). If I override the DPI settings for Rgui, then things are nice and crisp. Is this common knowledge?

25.02.2026 15:39 β€” πŸ‘ 6    πŸ” 0    πŸ’¬ 2    πŸ“Œ 0
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Benchmark comparison of for-loops versus apply()/sapply() in 3 different versions of R (2.5.0, 3.0.0, 4.2.0) Benchmark comparison of for-loops versus apply()/sapply() in 3 different versions of R (2.5.0, 3.0.0, 4.2.0) - output.txt

So many myths around loops in R as Juli said. Some specialized functions like rowMeans() are indeed faster but the *apply() family is not. A while ago, I did some benchmarking across R versions: gist.github.com/wviechtb/83e...

25.02.2026 07:54 β€” πŸ‘ 23    πŸ” 3    πŸ’¬ 3    πŸ“Œ 0

Oh please make this happen! This kind of REPL like functionality is so essential.

10.01.2026 12:18 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Owning a house is how I personally verified the Second Law of Thermodynamics: If you stop adding energy, money, and time into it, everything falls apart.

15.12.2025 09:11 β€” πŸ‘ 5    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Cartoon picture of an artillery fun shooting a bunch of questionnaires at a person with the words "A BATTERY OF QUESTIONNAIRES" at the top.

Cartoon picture of an artillery fun shooting a bunch of questionnaires at a person with the words "A BATTERY OF QUESTIONNAIRES" at the top.

Whenever I read 'battery of questionnaires', I think of ...

27.10.2025 11:30 β€” πŸ‘ 8    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Given that John Watts studied psychology, you can't tell me that the band name Fischer-Z is not actually based on Fisher's r-to-z transformation (and that the 'fish's head' pun was invented later).

07.10.2025 08:47 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

For people in #academia -- What's the oldest email in your inbox that you still plan to respond to at some indeterminate timepoint in your life? (in other words: Please make me feel better about my inbox of shame)

16.09.2025 09:32 β€” πŸ‘ 3    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
a man with red hair and a beard is standing in the woods Alt: A man with red hair and a beard is standing in the woods and giving an approving nod.

You arrive at #Oslo airport, stand at the baggage claim, wonder why you have wifi, and realize that #eduroam works in the entire airport.

04.09.2025 07:35 β€” πŸ‘ 12    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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Structural and practical identifiability analysis of partially observed dynamical models by exploiting the profile likelihood Abstract. Motivation: Mathematical description of biological reaction networks by differential equations leads to large models whose parameters are calibra

This one also touches on the same issues: doi.org/10.1093/bioi...

27.08.2025 14:30 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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plotannotate: Annotate Plots Interactively annotate 'base R graphics' plots with freehand drawing, symbols (points, lines, arrows, rectangles, circles, ellipses), and text. This is useful for teaching, for example to visually exp...

The plotannotate package (#RStats) is now on CRAN:

cran.r-project.org/package=plot...

The package allows users to annotate base R graphics plots with freehand drawing, symbols, and text. This is useful for teaching (e.g., to visually explain certain plot elements) and creating quick sketches.

23.08.2025 09:10 β€” πŸ‘ 23    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
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A review of spline function procedures in R - BMC Medical Research Methodology Background With progress on both the theoretical and the computational fronts the use of spline modelling has become an established tool in statistical regression analysis. An important issue in splin...

The paper about splines in R that I wish I had known about when I was learning splines in R.

bmcmedresmethodol.biomedcentral.com/articles/10....

22.08.2025 16:51 β€” πŸ‘ 42    πŸ” 7    πŸ’¬ 1    πŸ“Œ 1

That's using Command, right? Control should given "ctrl-f" (and so on).

19.08.2025 14:45 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Yeah, Command isn't captured by getGraphicsEvent(). But Control works as intended. Thanks!

19.08.2025 14:44 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

I got confirmation over at Mastodon that this returns ctrl-F ctrl-B, and ctrl-I (as expected).

19.08.2025 14:18 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Would somebody using #Rstats under macOS be so kind and do the following:

x11()
plot(1)
getGraphicsEvent(onKeybd=function(key) return(key))

then click on the plot, and hit control-f (and the same with control-b and control-i) and tell me what it shows in the console?

19.08.2025 13:36 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 3    πŸ“Œ 1

Happy to finally share the preprint for our work on how affective inertia differs within-days and overnight (with Stacey Scott, Martin Sliwinski, Josh Smyth, @wviechtb.bsky.social chtb.bsky.social‬ and @aneubauer.bsky.social) 1/4

10.07.2025 09:00 β€” πŸ‘ 14    πŸ” 3    πŸ’¬ 2    πŸ“Œ 0

You might be underestimating how nerdy the crowd is. A considerable part of the people in that group grew up with C64s and fondly remember cracker intros and the demo scene.

27.06.2025 12:12 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Depends on what the code is doing. Some things can benefit greatly from parallel processing, others not at all. But in the former case, users can usually do the parallelization themselves (esp. for problems that are embarrassingly paralizable), so then rewriting code in C might be more useful.

25.06.2025 10:04 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Video thumbnail

Interested in research synthesis, meta-analysis, systematic reviews, methodology, software, guidelines, best practices? πŸ˜€ πŸ“Š

This #YouTube channel is really the best spot to learn and meet our community! πŸ‘‡

14.06.2025 14:52 β€” πŸ‘ 29    πŸ” 13    πŸ’¬ 2    πŸ“Œ 2
A "Mr. McMahon reaction meme" where McMahon shows increasing levels of amazement/excitement, with levels "I^2", "tau^2", and "prediction interval", and "predictive distribution".

A "Mr. McMahon reaction meme" where McMahon shows increasing levels of amazement/excitement, with levels "I^2", "tau^2", and "prediction interval", and "predictive distribution".

12.06.2025 10:55 β€” πŸ‘ 17    πŸ” 4    πŸ’¬ 0    πŸ“Œ 0
ESMARConf2025: Keynote - Misunderstandings and misuses of commonly-cited methods... - Julian Higgins
YouTube video by ESMARConf ESMARConf2025: Keynote - Misunderstandings and misuses of commonly-cited methods... - Julian Higgins

Planning to do a systematic review?
Do watch this very informative presentation first!
Julian Higgins talks about improper use of:

PRISMA reporting guideline
I-squared statistics
Test for asymmetry in funnel plots
Random effects model

#ESMARConf2025

m.youtube.com/watch?v=wRA0...

11.06.2025 15:03 β€” πŸ‘ 8    πŸ” 3    πŸ’¬ 0    πŸ“Œ 0

I love auto translations. "The Tasmanian-led approach to random-effects meta-analysis". πŸ˜• Didn't know that there was a Tasmanian school for meta-analysis! Learning something new every day. #ESMARConf2025

11.06.2025 14:12 β€” πŸ‘ 6    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
ESMARConf2025: Tutorial metaselection: Meta-analytic selection models with... - James Pustejovsky
YouTube video by ESMARConf ESMARConf2025: Tutorial metaselection: Meta-analytic selection models with... - James Pustejovsky

Super interesting talk by James Pustejovsky (@jepusto.bsky.social) and Martyna Citkowicz at #ESMARConf2025 on the metaselection package, which provides cluster-robust inference methods and clustered bootstrapping to account for dependencies in selection models: youtu.be/2qGcVeEqtBY

11.06.2025 12:21 β€” πŸ‘ 9    πŸ” 3    πŸ’¬ 0    πŸ“Œ 0
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ESMARConf About ESMARConf The Evidence Synthesis Hackathon’s (https://www.esmarconf.org) Evidence Synthesis & Meta-Analysis in R Conference (#ESMARConf2025) will take place on 11th-13th of June 2025. ESMARConf ...

#ESMARConf2025 is live (www.youtube.com/@esmarconf), starting with a talk by @asanchez-tojar.bsky.social on "Practising what we preach: Rethinking standards in meta-analysis for ecology and evolution". At 11am CEST, I will give a talk on how to visualize the amount of heterogeneity in forest plots.

11.06.2025 08:27 β€” πŸ‘ 6    πŸ” 1    πŸ’¬ 0    πŸ“Œ 1

On Thursday evening during my weekly live stream on R and statistics, I will do something meta-analysis related in connection with #ESMARConf2025. Further details about my live streams can be found here: www.wvbauer.com/doku.php/liv...

10.06.2025 12:10 β€” πŸ‘ 3    πŸ” 2    πŸ’¬ 0    πŸ“Œ 0
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2025 - ESMARConf

Just a reminder that #ESMARConf2025 is starting tomorrow! This is a free online conference about evidence synthesis and meta-analysis using #Rstats. Further details can be found here: esmarconf.org/2025/

10.06.2025 12:08 β€” πŸ‘ 16    πŸ” 10    πŸ’¬ 0    πŸ“Œ 0
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Tuberculosis still kills around 1.3 million people every year.

It was once a massive killer in Europe and the US, but not anymore. How did these countries manage to tackle it?

Our first article on TB in a three-part series: ourworldindata.org/tuberculosis...

09.06.2025 06:17 β€” πŸ‘ 76    πŸ” 23    πŸ’¬ 6    πŸ“Œ 0