Stats & bats

To intercept or not to intercept? Is that a question when calculating indices?
statistics
Long-term trends in the abundance of species are often communicated as indices. The abundance at some reference point in time is set at 100%. Sometimes this point in time is…
Thierry Onkelinx
2018-11-01

Required number of levels for a random effects
statistics
mixed-models
When we analyse a mixed models, the question…
Thierry Onkelinx
2018-09-03

Comparing inlabru with INLA
statistics
mixed-models
inlabru is an R package which builds on top of the INLA package. I had the opportunity to take a workshop on it during the International Statistical Ecology Workshop ISEC2018 in St Andrews. This was a five day workshop condensed into a single day, hence the pace was very high. It gave us a good overview of the possibilities…
Thierry Onkelinx
2018-07-12

Bat silhouettes at 1:1 scale
bats
Hillie Waning Vos posted a message in the Facebook group“vleermuizen” showing how she created some bat silhouettes at 1:1 scale. This is useful to illustrate the true size of bats to the public. She took a simple template and re-sized it to…
Thierry Onkelinx
2018-05-19

Temporal autocorrelation in INLA
statistics
mixed-models
One of the reason why I often use INLA is because it allows for correlated random effects. In this blog post, I will handle random effect with temporal autocorrelation. INLA has several options for this. There are two major types of model, the first handles discrete time step, the latter continuous time…
Thierry Onkelinx
2018-03-05

Highly correlated random effects
statistics
mixed-models
Recently, I got a question on a mixed model with highly correlated random slopes. I requested a copy of the data because it is much easier to diagnose the problem when you…
Thierry Onkelinx
2018-02-16

Review of the ReadRPA software
bats
tool review
The default way to download recordings from a Peersonic bat detector is to connect the detector via a USB cable to the computer and copy them to the computer. The file transfer rate is quite low. In case you have to copy 100 to…
Thierry Onkelinx
2017-09-26

A git workflow for ecologists
reproducible research
version control
For those how don’t know git, it is a free and open source distributed…
Thierry Onkelinx
2017-08-23

Using a variable both as fixed and random effect
statistics
mixed-models
One of the questions to answer when using mixed models is whether to use a variable as a fixed effect or as a random effect. Sometimes it makes sense to use a variable both…
Thierry Onkelinx
2017-08-23

Peersonic bat-detector in waterproof IP67 enclosure
bats
tool review
I’ve reviewed the standard version the Peersonic RPA2 bat-detector in an earlier blog post. Today I will take about the RPA2 in a waterproof IP67 enclosure and my experiences on using it as on…
Thierry Onkelinx
2017-07-29

Nested and crossed random effects in lme4
statistics
mixed models
People often get confused on how to code nested and crossed random effects in the lme4 package (Bates et al. 2015). I…
Thierry Onkelinx
2017-07-18

Creating continuous coloured maps with osmplotr
reproducible research
maps
During useR!2017 I attended a talk by Mark Padgham titled Maps are data, so why no plot data on a map. In this blog post I will recreate the map from an earlier blog post on estimating densities from a point…
Thierry Onkelinx
2017-07-17

Peersonic RPA2 bat detector and low frequencies
bats
tool review
Recently René Janssen from Bionet Natuuronderzoek was looking for an…
Thierry Onkelinx
2017-07-14

Estimating densities from a point pattern
statistics
point pattern
In this example we focus on a…
Thierry Onkelinx
2017-06-28

Some things I learned about bookdown::gitbook
reproducible research
text
Bookdown is an R package that makes writing technical documents based on R much easier. One of the nice things is that you can create a corporate identity using LaTeX styles for pdf…
Thierry Onkelinx
2017-06-26

Analysing data from bat observations along transects
bats
analysis
This post will…
Thierry Onkelinx
2017-06-15

Review of the Peersonic RPA2 bat detector in the field
bats
tool review
I will compare the Peersonic RPA2 with the combination of a Petterson D240x and a Roland Edirol R-05 recorder. Mainly because I have a lot of experience with the D240x - Edirol combo. Both set-ups are useful when a…
Thierry Onkelinx
2017-06-11

Introduction
about
I have no idea where this blog will lead. Current plans are a review of the PeerSonic bat detector, some examples of how bat detector observations can be analysed and some questions that I get…
Thierry Onkelinx
2017-06-10
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