Bert van der Veen

Bert van der Veen

@vdveenb.bsky.social

Postdoc in Statistical Ecology @unibayreuth.bsky.social | (model-based) Ordination, mixed-models and some ecology #GLLVM | https://github.com/BertvanderVeen

969 Followers 371 Following 313 Posts Joined Oct 2023
1 week ago
Preview
We are hiring: PhD position in Ecological Data Science We are looking for a PhD student to join the AG Hartig (Theoretical Ecology) in the field of ecological data science / deep learning. 

#PhDPosition in Ecological #DataScience in our group. For details, see www.uni-regensburg.de/universitaet... #MachineLearning #AI #DeepLearning #Statistics #Ecology #AcademicJobs

20 19 1 0
10 hours ago

No worries, this is clear. It confirms what I thought, so my response remains unchanged.

gllvm does not specify the random effects covariance matrix in the same way, it is for the covariate effects instead, so that for a single covariate you get only a variance.

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12 hours ago

If "trait" is not passed as covariate but as keyword, this may exactly be what gllvm does with formula = ~ (covariate|1), I think as the columns are implicit.

Random effects are assumed to be specific to the columns.

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12 hours ago

Yes.

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12 hours ago

What does that mean for the covariance matrix for that random term?

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13 hours ago
In this article, we present the case for Generalized Linear Latent Variable Models (GLLVMs) as a go-to choice of statistical method for any community ecologist wanting to tackle a range of present-day ecological research questions. GLLVMs bring tools and capabilities from classic (mixed-effects) regression models to multivariate community analysis, providing a number of novel ways to tailor models specifically to one’s study questions and data properties not available when using non-model-based multivariate methods. In order to facilitate further adoption of these methods by community ecologists, we provide 1) a practitioner-focused and practical overview of the advantages the GLLVM framework brings to the table when addressing different core ecological questions, 2) a number of concrete suggestions for how GLLVMs best can be incorporated into the analytical workflow of community ecologists, and 3) two illustrative worked examples of this workflow in action on real-world data.

Nice! A Practitioner’s Guide to Latent Variable Modelling for Community Ecology doi.org/10.32942/X2K... #ecopubs

6 2 1 0
14 hours ago

It may be possible to trick gllvm by smartly formulating the data and adding some NAs, but it's going to be painful.

Unless I misunderstand what MCMCglmm does exactly.

0 0 2 0
14 hours ago

'formula' assumes column-specific random effects with a covariate by covariate covariance matrix.

So here, 'line' is a single covariate, so you'll get a single variance parameter.

No reason why gllvm could not do something else but we did not have the foresight that someone would try this.

0 0 1 0
14 hours ago

The difficulty is that MCMCglmm passes 'trait' as covariate, whereas it also corresponds to the responses?

gllvm is not quite setup to accommodate a structure like that (yet?), as covariates are assumed to not be response-specific.

1 0 3 0
14 hours ago
Personīgais numerologs - Num.lv

I'm not very familiar with the MCMCglmm syntax unfortunately, but....

- The 'family' argument is specified in the same way
- an unstructured residual covariance is not possible in gllvm (well, via LVs... so num.lv =..)
- formula = ~(0+line|trait) conceptually corresponds to 'random', I think.

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14 hours ago

Bluesky works, e-mail works, github discussions works too. I'm not particularly picky.

In case you're looking for an answer from Jenni Niku instead, e-mail or github, because I believe she is not on bluesky.

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1 day ago

@rtbecard.bsky.social

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1 day ago
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Registration is now open for the Physalia online course GLLVMs: Advanced Multivariate Analysis in R (7–10 July) led by
@vdveenb.bsky.social

Join us to learn model-based ordination, JSDMs, and multispecies GL(M)Ms. Hands-on in R!

www.physalia-courses.org/courses-work...

#Ecology #RStats #GLLVM

7 3 1 1
1 day ago
Preview
University of Bayreuth launches elite master’s programme in Ecological Forecasting University of Bayreuth: Our liveable campus university offers innovative, interdisciplinary degree programmes and good career opportunities.

University of Bayreuth launches elite master’s programme in Ecological Forecasting
www.uni-bayreuth.de/en/press...
#Elitestudiengang #UBT #UniBayreuth #Ecological #Forecasting #StudierenInBayreuth

8 4 0 2
5 days ago

Shared from my PhD lab’s WhasApp chat, how a journal published a paper about the Arctic fox which is 100% an AI hallucination, and journal isn’t retracting it.

www.canids.org/resources/Le...

Damn depressing how fake science and AI is increasingly flooding real science and real work.

36 17 1 0
1 week ago

Send help @gsimpson.bsky.social.

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1 week ago

I find myself writing an argument for #GAMs.

My data generating process is multivariate, but the univariate outcome is non-linear, so I can design a GAM that predicts well, while being an utterly misspecified model.

Is this how it starts? Am I part of the GAM cult now?

4 0 1 0
1 week ago
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The next round of NSO Grants is now open! Apply by 29th April for the Networking and Education or the Early-Career Researcher Grant. Check out full application guidelines here: vist.ly/4tpjk
and become a member before applying: vist.ly/4tpjh

7 8 1 0
1 week ago

🎉 It's livestream day 🎉

Join me at 1700 (CET; 1600 UCT) today for two hours of GAM goodness 🤤

📽️ Youtube: youtube.com/live/A9U8e1K...
Hit the Notify me 🔔 to get a reminder when I go live

#RStats #mgcv #statistics #GAMs #DataScience 🧪

39 21 2 1
1 week ago

Hehe, not really. If there are sufficient colleagues, and there is some travel funding, drop me an email at Bert.van-der-Veen@uni-bayreuth.de and we can see what may be arranged.

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1 week ago
GitHub - BertvanderVeen/GLLVM-workshop: Physalia workshop on Generalized Linear Latent Variable Models by Bert van der Veen Physalia workshop on Generalized Linear Latent Variable Models by Bert van der Veen - BertvanderVeen/GLLVM-workshop

Yes, I organised a few last year. Thanks for noticing!

I don't have many plans yet for this year, but that can always change if there is sufficient interest.

At least I will organise the workshop with @physaliacourses.bsky.social again github.com/BertvanderVe..., but plans are not yet concrete.

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2 weeks ago

Oh, I don't care in which repository the data is archived.

This issue has cropped up in various flavours. Most recently it concerned a paper that was supposed to archive the data upon publication in dryad, but it wasn't actually submitted to dryad, and this paper wasn't published recently either.

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2 weeks ago

I'm getting real sick and tired of journals referring me to either a) the authors or b) data dryad, when I inquire after a paper's data, that was promised in the data statement.

Surely, if data archiving is promised, the journal and publisher have a responsibility for seeing this through. #ecoevo

10 0 1 0
3 weeks ago
a graph showing how LLMs do or do not p-hack

While LLMs will try to follow good research practices by default, you can pretty easily convince them to p-hack for you. In one case (out of the 4 tested), the LLM moved the result from p > 0.05 to p < 0.001. github.com/janetmalzahn...

32 13 1 3
3 weeks ago

Come work with us! 🧪🌐🧑‍💻🌿🐸❄️

I am hireing a #postdoc in Climate Change Ecology to work on Ecological Synthesis and support the upcoming #IPCC report as a Chapter Scientist (CH14: terrestrial, freshwater and cryopspheric biodiversity, ecosystems, and services. #IPCC #AR7
@ipcc.bsky.social

50 44 0 0
3 weeks ago

It'll probably make it to CRAN in March.

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3 weeks ago

Please don't old your breath, #gllvm management may take a day to get back to me.

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3 weeks ago

One moment, will check

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1 month ago

Ooh, I like Laplace priors now.

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1 month ago
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Seats still open for the GLMs in R course with @vdveenb.bsky.social l! Bert’s a top-notch instructor—dive deep into GLMs as a powerful, flexible framework for all kinds of data analysis. Don’t miss out!

www.physalia-courses.org/courses-work...
Please share with anyone who may be interested!

#GLMs

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