Matthijs Hollanders
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matthollanders.bsky.social
Matthijs Hollanders
@matthollanders.bsky.social
Quantitative ecology, statistics, wildlife, field herping.

Post-doctoral Research Fellow @ U of Canberra
Consultant @ Quantecol, https://quantecol.com.au
Wildlife tour guide @ Australian Wildlife Encounters, https://www.australianwildlifeencounters.com
I can’t stand that online journals can’t format equations properly.
May 29, 2025 at 8:37 PM
What do people think of this?

ai-2027.com
AI 2027
A research-backed AI scenario forecast.
ai-2027.com
May 18, 2025 at 7:52 AM
Hey #stats people, what do we think about interpreting coefficients in cloglog binomial regressions? Since everyone hates odds ratios I wonder if interpreting hazard ratios is easier.
May 13, 2025 at 11:03 AM
Why do we peer review for free?
May 1, 2025 at 6:43 AM
I need some help with parameterising a latent simplex, so a set of latent probabilities that sum to 1. Can anyone have a yarn?
April 3, 2025 at 5:39 AM
Hazard rates FTW 🎉
By default, mark-recapture models parameterise the survival process with survival probabilities. This is unfortunate, because logit-linear survival functions aren't time invariant, and you can't just exponentiate multistate transition probabilities like you can survival. Instead, we should... 1/2
April 2, 2025 at 10:22 AM
brms is one of the most amazing R packages ever. Nevertheless I can't get myself to use it for my own work because nothing beats coding up your own models where you have ultimate control and insight into what's going on. There remains a "black box" element unless you are deeply familiar with it.
March 29, 2025 at 11:48 PM
Working on a multisite/multistate/robust design Jolly-Seber model in Stan where I need to marginalise (1) the entry occasion of each individual and (2) the sub-area within each site where each individual enters. 😮‍💨
March 17, 2025 at 3:42 AM
Reposted by Matthijs Hollanders
We just updated our HMM blog by applying the backward sampling algorithm to recover the posterior distributions of latent states. Check it out!

quantecol.com.au/blog/hmm-in-...
Ecological Modeling in Stan
quantecol.com.au
February 24, 2025 at 10:38 AM
Hey movement ecology people, are the models implemented in the #ctmm R package essentially just GPs fit to location data?
February 21, 2025 at 2:38 AM
Launched a bsky page for the ecological stats consultancy, give us a follow!
Quantecol is on Bluesky! We are a statistical consultancy specialised in (but not limited to) quantitative ecology. We also blog about ecological statistics, with our latest post being about fitting various ecological models in Stan. quantecol.com.au/blog/margina...
Quantecol - Marginalisation
quantecol.com.au
February 12, 2025 at 5:03 AM
Those are good looking plots.
{tinyplot} 0.3.0 is out! 🚨

It's a lightweight #Rstats 📦 to draw beautiful and complex plots, using an ultra-simple and concise syntax.

This is a massive release! @gmcd.bsky.social @zeileis.org and I worked hard to add tons of new themes and plot types.

Check it out!

grantmcdermott.com/tinyplot/
February 6, 2025 at 11:35 AM
Reposted by Matthijs Hollanders
Another video in my series on applied time series and forecasting with the {mvgam} #rstats 📦. This one introduces State Space hierarchical GAMs and GPs for tackling multivariate series youtu.be/2POK_FVwCHk?...
Time series in R and Stan using the mvgam package: hierarchical GAMs
YouTube video by Nicholas Clark
youtu.be
February 4, 2025 at 8:09 AM
New blog post! I show how to marginalise discrete variables from Bayesian ecological models in Stan and how to recover their posterior distributions after estimation. I cover occupancy and N-mixture models using multiple parameterisations and model types. quantecol.com.au/blog/margina...
Quantecol - Marginalisation
quantecol.com.au
February 4, 2025 at 2:53 AM
I've been looking at different parameterisations of multi-season occupancy models, and it seems that dynamic (with colonisation and emigration) and auto-logistic models aren't all that different. Auto-logistic might be preferred with \alpha being a sort of average log odds.
@masonfidino.bsky.social
January 7, 2025 at 10:40 PM
I’ve been enjoying a restful Christmas break, and one of the highlights was this python selecting a carefully placed tin stack to lay her eggs.
January 1, 2025 at 4:21 AM
Hey guys, how do you do posterior predictive checks for GPs?
November 27, 2024 at 4:11 AM
It’s hard to beat an afternoon of herping our Gondwana rainforests. Big coastal carpet python under tin and a gravid snake-tooth skink on the crawl were amongst the many finds over the weekend.
November 17, 2024 at 9:30 PM
Paul Bürkner's brms book is really good.

paulbuerkner.com/software/brm...
paulbuerkner.com
November 13, 2024 at 5:18 AM
I forgot about this app until just now. Might use my first post in a while to shill my blog, where I recently wrote a new post about using Gaussian processes for random temporal and/or site effects in (ecological) models.

quantecol.com.au/blog/gaussia...
Quantecol - Default to Gaussian processes
quantecol.com.au
November 12, 2024 at 3:24 AM
As a first post on Bluesky I'll shill our recently launched #statistics blog, where we'll be focusing on applied statistical ecology in particular. Our first post details a scalable method for fitting increasingly complex hidden Markov models in Stan. quantecol.com.au/blog/hmm-in-...
Quantecol - Ecological Modeling in Stan
May 5, 2024
quantecol.com.au
May 9, 2024 at 12:12 AM