All Questions
Tagged with beta-binomial or beta-binomial-distribution
191 questions
1 vote
0 answers
38 views
Estimating the latent variable distribution out of compound distribution
I am new to this community, and please tell me if something is off standards. I currently have $P$ number of exchangeable, correlated, identically distributed Bernoulli random variables. Let $X_1, X_2,...
- 111
2 votes
1 answer
88 views
Is a low R² for Beta-binomial regression an issue?
I am studying a large dataset of animals subjected to 2 treatments. I aim to assess the impact of treatment on mortality rate. For each observation, I have the number of individuals dead or alive ...
- 73
0 votes
0 answers
46 views
glmmTMB warns of false convergence with betabinomial models but no with bin or negbin models
I've been looking for the best distribution to fit a glmm model to my data. The best seems to be a betabinomial model, but it gives a warning about false convergence, which is caused by large z values:...
- 163
2 votes
1 answer
104 views
How to get around warning for using a matrix response to calculate R2 for a beta-binomial distribution?
I have a proportion response (success, failures) in my beta binomial GLM. However when I try to use performance package to calculate pseudo r2 I get the following warning: Warning message: Can't ...
- 171
0 votes
0 answers
46 views
Beta-binomial mixed model: spline of time as fixed effect, keep random slope for time if variance is very small but LRT significant?
I’m modeling longitudinal substance use (number of days consumed over 30 days) for ~930 patients with repeated measures. The outcome is modeled with a beta-binomial distribution (logit link, glmmTMB ...
- 23
2 votes
1 answer
232 views
Beta-binomial vs binomial GLMM for modeling longitudinal 0–30 day substance use outcomes: DHARMa, dispersion, zero-inflation, prediction issues
Context : I’m working with a longitudinal cohort of patients followed for substance use disorders (n ≈ 3300 observations, 900 subjects). The outcome is the number of days of substance use over the ...
- 23
4 votes
1 answer
91 views
Beta Binomial distribution conditional on realized gamma value
I am looking to derive the formula for the conditional probability distribution of a beta-binomial random variable $W$ conditional on value of a gamma random variable that drives the beta. The ...
- 41
1 vote
0 answers
46 views
Best loss function for predicting relative speed of two (or more) options
I want to create a model that tries to predict which execution engine will be faster for a given user query. The model does not have enough information to predict the actual run time, but we want to ...
- 141
1 vote
0 answers
45 views
Optimization fails to converge on known parameters for zero-inflated beta binomial distribution [closed]
I am trying to fit to simulated zero-inflated beta binomial data using the distributions provided by VGAM in R. When using optim on a likelihood function I wrote, ...
- 11
0 votes
0 answers
121 views
Beta-binomial relationship between dispersion and correlation parameters
Context: I have created a beta-binomial model using glmmTMB() from the glmmTMB package and I am now trying to simulate a beta-...
- 13
1 vote
0 answers
385 views
What are the assumptions of beta-binomial models, and how do I test for them in r?
I want to model the effects of dispersal distance (disp) and reproductive rate (rep) on colonization rate, quantified as the ...
- 11
1 vote
0 answers
104 views
Distributional choices for sparse 0,1 data
I am using GAMs to model the relationship between a binary response variable (0 or 1) and several continuous fixed and random explanatory variables. It seems that a binomial distribution is the ...
- 11
3 votes
1 answer
131 views
What is the correct implementation of MCMC
I am learning Markov Chain Monte Carlo (MCMC) simulation as of the moment. My background is civil engineering and please excuse my ignorance if some of the questions are quite obvious. I want to learn ...
- 41
2 votes
2 answers
226 views
prior and posterior predictive distributions, Bayes Theory
Consider the binomial sampling model with a Beta prior on $\theta$ and the prior predictive distribution. Let $n$ be the binomial sample size. \begin{align} p(y^{new}) &= \int_{\theta}f(y^{new}|\...
- 31
1 vote
2 answers
180 views
Posterior of binomial and mixed prior
I'm currently studying posterior distribution with likelihood $y|\theta \sim B(n,\theta)$ and mixture of prior distribution $\theta \sim \pi Beta(\alpha_1, \beta_1) + (1-\pi)Beta(\alpha_2, \beta_2)$. ...
- 311