All Questions
Tagged with dirichlet-distribution prior
13
questions
2
votes
0
answers
162
views
Choosing the Dirichlet prior in a mixture model
Consider the following mixture model with $K < \infty$ components,
$$
f\left(x \mid \theta_{1}, \ldots, \theta_{K}, \pi_{1}, \ldots, \pi_{K}\right)=\sum_{k=1}^K \pi_{k} \varphi\left(x \mid \theta_{...
- 387
1
vote
1
answer
366
views
Parametrization of Dirichlet distribution
Hej!
Consider I have a Dirichlet distribution with 4 variables, where the mean (u) values of these are known. $(u1+u2+u3+u4=1)$
Now, I want to obtain the parameters of the Dirichlet distribution ($\...
- 11
3
votes
2
answers
2k
views
What is a non-informative choice of parameters for a Dirichlet distribution?
Dirichlet distribution is a conjugate prior for multinomial distribution. I want to impose a non-informative prior over sampling weights $\pi$ for a draw $x=(x_1,…,x_N)$ from a multinomial ...
- 655
0
votes
1
answer
158
views
LDA alpha equivalent in structural topic model
I'm using an implementation of the structural topic model (stm), written in R using the stm package.
I want to reduce the number of topics that are prevalent in ...
- 25
1
vote
0
answers
226
views
Dirichlet process and clustering
How does clustering with a Dirichlet process as prior work? I am confused as to if the parameter $\alpha_i$ $\sim$ DP is found via clustering or is used to cluster. I undestrand how it can be used to ...
- 11
1
vote
1
answer
496
views
Prior for the regression coefficients in the logistic regression
I'm trying to model Bayesian logistic regression model with my dependent variable (status: 0=alive, 1 death) & independent variable (age) in the categorical form (0=patients < 65 yrs old, 1=...
- 21
1
vote
0
answers
370
views
KL divergence between discrete data and model (choosing hyperprior over Dirichlet concentration parameter $\alpha$)
I have some categorical data that follow an unknown true multinomial distribution $p$ and a model with known multinomial distribution $q$.
I want to estimate the KL divergence between $p$ and $q$ ...
- 5,226
2
votes
1
answer
1k
views
What is meant by "non-convex prior" and "sparsity-inducing prior"?
I was reading how to use collapsed gibbs sampling for latent dirichlet allocation in a google group and one user talked about using dirichlet priors with small hyperparameters and sum out the z ...
- 163
2
votes
1
answer
175
views
Dirichlet Process Clustering Prior
I'm doing dirichlet process clustering where dirichlet priors are used as:
with CRP representation as:
First customer will always choose first table.
Second will choose already occupied table with
...
- 201
3
votes
1
answer
132
views
Is it possible to define the mean of a varying distribution?
Suppose $(p_1,\ldots,p_k)$ be the vector of multinomial parameters and $$(p_1,\ldots,p_k)\sim \mbox{Dirichlet}(\alpha_1,\ldots,\alpha_k).$$
Let's define a function $f(p_1,\ldots,p_k) \in \mathbb{R}$. ...
- 51
16
votes
3
answers
5k
views
Why does nobody use the Bayesian multinomial Naive Bayes classifier?
So in (unsupervised) text modeling, Latent Dirichlet Allocation (LDA) is a Bayesian version of Probabilistic Latent Semantic Analysis (PLSA). Essentially, LDA = PLSA + Dirichlet prior over its ...
- 1,247
4
votes
2
answers
9k
views
What are typical values to use for alpha and beta in Latent Dirichlet Allocation?
Specifically in the case where I don't know anything about the documents I'm working with. I'm looking a specific number or number range.
- 141
9
votes
1
answer
4k
views
Bayesian inference for multinomial distribution with asymmetric prior knowledge?
Suppose I will be getting some samples from a binomial distribution. One way to model my prior knowledge is with a Beta distribution with parameters $\alpha$ and $\beta$. As I understand it, this is ...
- 4,791