Questions tagged [dirichlet-regression]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
0answers
21 views

Compare dependent categories over time?

I have a dataset with 50 individuals. 25 are exposed to a substance on low concentration, 25 are exposed to a substance on high concentration over time. I have 4 categories that represent different ...
0
votes
0answers
17 views

Testing for equality in single-response-category proportions in a multinomial sample

Problem: I have a multinomial variable with three response categories. I am asked to test the effect of certain categorical predictors on the proportion of each category. To my understanding, this ...
1
vote
2answers
217 views

Is it possible to fit a Dirichlet Regression to changing response variables?

A toy problem to illustrate my issue: We put a 100 people in a room with 10 candy bars. Each bar is different and has a different brand, flavor, size, color, etc. We ask each person in the group to ...
1
vote
1answer
37 views

Modeling probability mass over time for prediction

Consider a discrete random variable $X$ with three possible realizations $x_1,x_2,x_3$. This variable is observed over time, with the number of observations per point in time varying. The top ...
0
votes
0answers
90 views

Is fair to compare Dirichlet to a Multivariate Beta regression?

I am conducting some analysis on my data I found a strange behavior and would greatly appreciate some guidance or suggestions. I am trying to investigate the effect of a categorical variable (cl) to ...
1
vote
0answers
12 views

Including features in a Dirichlet model with Markov dynamics

I have a fantasizing about a model here, so please keep in mind that this is not even half-baked: I have categorical time series data $y_t\sim\text{Cat}(y\ |\ \lambda_t)$ with a hidden variable $\...
26
votes
3answers
2k views

Why Beta/Dirichlet Regression are not considered Generalized Linear Models?

The premise is this quote from vignette of R package betareg1. Further-more, the model shares some properties (such as linear predictor, link function, ...
1
vote
0answers
73 views

Dirichlet-Regression: Indicator for variable fit in model comparison

I have a number of Dirichlet regression models with differing forms (log, linear, polynomial etc) over a dirichlet distribution of 6 variables/Groups. An examplary output for summary(fit) in r would ...
3
votes
1answer
847 views

Interpretation of the Precision Model in Dirichlet regression

I use dirichlet regression to analyze the result of a membership matrix (compositional data). For each observation, I have membership probabilities to different groups and these probabilities sum to ...