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1 vote
1 answer
44 views

BIC with non-negligible priors

I want to do model selection based on the best-fit/MAP/marginal posterior I find from an MCMC and likelihood maximization. I have a likelihood $\mathcal{L}(X|\theta)$, some informative priors $\pi(\...
ojima's user avatar
  • 13
1 vote
0 answers
14 views

Importance sampling for a parameterized family of distributions using a wide distribution from the same family

I'm motivated here by a problem for robust Bayesian analysis. Let $l(Y|X)$ be the likelihood and let $\{p_\xi(X)\}$ be a parameterized family of prior distributions where $\xi$ denotes the ...
JDNC's user avatar
  • 11
2 votes
2 answers
636 views

Parameterization of inverse gamma prior in Bayesian methods

For a prior of $\sigma^2 \sim IG(0.01, 0.01)$, often recommended as an uninformative prior for the variance parameter in MCMC approaches and other Bayesian methods, which parameterization does this ...
bob's user avatar
  • 725
1 vote
1 answer
77 views

Is it ok to widen a prior during an MCMC which did not converge yet?

I am calibrating parameters of a process model. The runtime of the model is high and the calibration already ran for more than two weeks with many cores on a HPC. After almost 150k iterations I ...
Hans Jürgen's user avatar
1 vote
0 answers
107 views

Choosing between Gaussian/Laplacian prior distributions for MCMC regression

When doing a linear regression using MCMC, you have to specify prior distributions for the values of the regression coefficients of the independent variables. If all of the priors are Gaussian ...
HAL's user avatar
  • 173
0 votes
1 answer
255 views

Application of spike and slab for sampling from posterior distribution (bernoulli and beta)

I think the gamma N term in the first equation relates to the spike and prior. However, I am unsure what the rhs of the first is used for? Further, I am unsure what the pie term of the second equation ...
StatsBio's user avatar
  • 103
2 votes
0 answers
175 views

What are the bayesian prior distributions to use for a binomial model with unknown $n$ and $p$

I a experimenting with a new MCMC software and before I delve into more complicated models I wanted to run some simple simulations. This is a very very simple simulation, so not meant to be very ...
krishnab's user avatar
  • 1,522
0 votes
0 answers
36 views

Converting posteriors to likelihoods by removing prior

I have a set of MCMC chains (i.e., unnormalized posteriors) for a parameter I modeled for a sample of objects. I have a model that requires that I condition on the likelihoods of this parameter. My ...
Dex's user avatar
  • 101
0 votes
0 answers
73 views

How to parametrize a posterior to use it as a prior in Bayesian statistics?

In my problem, I have two sets of parameters, $\theta_1$ and $\theta_2$, and two datasets $d_1,d_2$ that constrain them with a known likelihood function. There is a certain 'hierarchy' in the model: ...
Ewoud's user avatar
  • 151
3 votes
1 answer
1k views

Priors and nested random effects in MCMCglmm?

I am trying to construct a zero inflation Poisson GLMM using MCMCglmm(). I am new to Bayesian Statistics and this function and I am struggling to understand a couple of things. For my data I am ...
Daniel Wade's user avatar
1 vote
1 answer
278 views

For Prior definition in bayesian regression with R package MCMCglmm, how to convey different strength of believe via parameter nu?

I understand the strength of the Prior is set via parameter nu however, I can not find information what nu expresses in statistical terms, e.g. how strong would a prior that is similar to the number ...
Tim M. Schendzielorz's user avatar
0 votes
1 answer
191 views

Setting priors for bivariate regression

I would like to perform a bivariate MCMC regression with boldness scores as the continuous response variable, aggression ranks as the ordinal response variable, trial numbers as fixed effect and ...
BP86's user avatar
  • 57
0 votes
0 answers
24 views

Sampling a proposed value with a limited range target when running MCMC [duplicate]

I want to do an MCMC algorithm and need to sample a proposed value from a proposed distribution. In the Metropolis algorithm, people usually use a normal distribution as proposal. But if the prior ...
yu zhang's user avatar
5 votes
1 answer
328 views

Why in Hamiltonian MCMC do we multiply the posterior distribution by the likelihood?

So maybe I am misunderstanding what the author is staying, but I am reading Chapter 14 of Kruschke's Doing Bayesian Analysis. I am reading about the software Stan and how it uses the Hamiltonian MCMC ...
confused's user avatar
  • 3,273
2 votes
0 answers
144 views

Posterior with a much larger uncertainty than the prior [closed]

I have done an MCMC analysis with many variables. One of my nuisance parameters has a Normal prior distribution with mean 0 and standard deviation 1. The posterior distribution for this parameter has ...
rhombidodecahedron's user avatar

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