Compositional data (proportions that sum to 1) behave in ways standard models aren’t built for
I walk through why Dirichlet regression is often the right tool & what extra insight it gives, using a real example of eyetracking
#Dirichlet #r #brms #guide #eyetracking #ordbetareg #tutorial #reanalysis #substack
#statstab #478 Stuck between Zero and One: Modelling Non-Count Proportions with Beta and Dirichlet Regression
Thoughts: A few resources for proportion data.
#Dirichlet #proportions #betareg #count #tutorial
https://methodsblog.com/2019/08/06/beta-dirichlet-regression_en/
Post provided by JAMES WEEDON & BOB DOUMA Chinese translation provided by Zishen Wang 這篇博客文章也有中文版 Imagine the scene: you’re presenting your exciting research results at an important internation…
#statstab #477 Simulating data for Dirichlet regression with varying estimates
Thoughts: Interesting thread about an underused model.
#Dirichlet #brms #poweranalysis #rstats #proportions #stan #forum
Hello everyone, The shortest formulation of my problem is the following: I’m trying to design a power analysis by simulation for a Dirichlet regression model using brms. How could we calculate the shape parameter alpha of the Dirichlet distribution by hand from a theoretical model in order to feed it to brms::rdirichlet(n, alpha) to simulate data with chosen effects? The goal is to tweak manually the coefficients of the model to simulate data with varying effect sizes. Now for the lengthier c...
#statstab #439 {ZOID}
Thoughts: "zero-and-one inflated Dirichlet regression (also known as trinomial mixture models) in a Bayesian framework (Stan)"
Useful for composite proportions.
Fits Dirichlet regression and zero-and-one inflated Dirichlet regression with Bayesian methods implemented in Stan. These models are sometimes referred to as trinomial mixture models; covariates and overdispersion can optionally be included.
#statstab #435 Guide to understanding the intuition behind the Dirichlet distribution
Thoughts: Useful for composite proportions, but take ages in brms.
#brms #Dirichlet #proportions #modelling #rstats #r #betareg
https://www.andrewheiss.com/blog/2023/09/18/understanding-dirichlet-beta-intuition/
Wir wünschen allen Alumni der #GAUG einen schönen Alumni-Tag u.a. bei uns im MI im Auditorium Maximum ab 13:00 mit folgenden Programm:
* Grußworte, Neues aus der Fakultät und Alumni Chapter (Dekanin Prof. Dr. Anja Sturm, Prof. Dr. Ralf Meyer)
* Festvortrag von Prof. Dr. Ina Kersten, Zum Leben und Werk von Gustav Lejeune #Dirichlet, Mathematiker und Nachfolger von Carl Friedrich #Gauß mit musikalischer Begleitung
* Jubilarsfeier mit Verleihung von Ehrenurkunden
* Empfang mit Getränken und Kuchen
Une avancée notable vers la résolution de l' #hypothèse de #Riemann .
Poir cela, #LarryGuth et #JamesMaynard utilisent des #polynômes de #Dirichlet et une meilleure borne de leurs zéros.
Référence : https://arxiv.org/abs/2405.20552
We prove new bounds for how often Dirichlet polynomials can take large values. This gives improved estimates for a Dirichlet polynomial of length $N$ taking values of size close to $N^{3/4}$, which is the critical situation for several estimates in analytic number theory connected to prime numbers and the Riemann zeta function. As a consequence, we deduce a zero density estimate $N(σ,T)\le T^{30(1-σ)/13+o(1)}$ and asymptotics for primes in short intervals of length $x^{17/30+o(1)}$.
'Choosing the Number of Topics in LDA Models – A Monte Carlo Comparison of Selection Criteria', by Victor Bystrov, Viktoriia Naboka-Krell, Anna Staszewska-Bystrova, Peter Winker.
http://jmlr.org/papers/v25/23-0188.html
#topics #lda #dirichlet
Dr Mircea Zloteanu 🌺🌞🍃
mq86mq
MI Göttingen
Rod2ik 🇪🇺 🇨🇵 🇪🇸 🇨🇱 🇺🇦 🇨🇦 🇬🇱☮🕊️
JMLR
Bjørnar (he/him)