Blog Archives

The completeness of online gun shooting victim counts

November 9, 2014
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The completeness of online gun shooting victim counts

There are a number of on line efforts to register victims of shootings online. Shootingtracker tries to register all mass shootings, those with four or more victims. Slate had the gun death tally (GDT), gun deaths starting at Newtown, running thro...

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Tuning Laplaces Demon IV

November 2, 2014
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Tuning Laplaces Demon IV

This is the last post of testing Laplaces Demon algorithms. In the last algorithms there are some which are completely skipped because they are not suitable for the problem. Reversible Jump is for variable selection. Sequential Metropolis-within-Gibbs,...

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Tuning Laplaces Demon III

October 26, 2014
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Tuning Laplaces Demon III

This is the third post with LaplacesDemon tuning. same problem, different algorithms. For introduction and other code see this post. The current post takes algorithms Independence Metropolis to Reflective Slice Sampler.Independence MetropolisIndependen...

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Tuning Laplaces Demon II

October 19, 2014
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Tuning Laplaces Demon II

I am continuing with my trying all algorithms of Laplaces Demon. It is actually quite a bit more work than I expected but I do find that some of the things get clearer. Now that I am close to the end of calculating this second batch I learned that ther...

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Tuning LaplacesDemon

October 12, 2014
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Tuning LaplacesDemon

I was continuing with my Bayesian algorithms in R exercise. For these exercises I port SAS PROC MCMC examples to the various R solutions. However, the next example was logit model and that's just too simple, especially after last week's Jacobian for th...

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Bayes models from SAS PROC MIXED in R, post 2

October 5, 2014
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This is my second post in converting SAS's PROC MCMC examples in R. The task in his week is determining the transformation parameter in a Box-Cox transformation. SAS only determines Lambda, but I am not so sure about that. What I used to do was get an ...

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Bayesian models in R

September 28, 2014
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Bayesian models in R

There are many ways to run general Bayesian calculations in or from R. The best known are JAGS, OpenBUGS and STAN. Then some time ago Rasmus Bååth had a post Three ways to run Bayesian models in R in which he mentioned LaplacesDemon (not on CRAN) on top of those. A check of the Bayes task view...

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Trying dplyr on triathon data

September 21, 2014
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Trying dplyr on triathon data

There was a triathlon in Almere last week, like every year since 1983. I pulled the data of all years to get some idea how things have changed in that sport. To get a visual I decided to plot the best 10% athletes. Then later I decided this was an idea...

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Trying a prefmap

September 14, 2014
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Trying a prefmap

Preference mapping is a key technique in sensory and consumer research. It links the sensory perception on products to the liking of products and hence provides clues to the development of new, well tasting, products. Even though it is a key technique,...

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Mapping products in a space

September 7, 2014
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Mapping products in a space

I have read about people doing a Bayesian PCA at some points and always wondered how that would work. Then, at some point I thought of a way to do so. As ideas evolved my interest became not PCA as such, but rather in a prefmap. As a first step in that...

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