Blog Archives

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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Beta binomial revisited

August 31, 2014
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I got some comments on my priors of last week's post where better priors were proposed. Hence this week's post looks at them. After some minor adaptations, since I have nine beta parameters and beta needs to be fairly high, I can conclude that these pr...

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JAGS and Stan

August 24, 2014
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JAGS and Stan

During the last year I have been running some estimations in both JAGS and Stan. In that period I have seen one example where JAGS could not get me decent samples (in the sense of low Rhat and high number of effective samples) but that was data which I...

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Quicksort speed, just in time compiling and vectorizing

August 17, 2014
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Quicksort speed, just in time compiling and vectorizing

I was reading the Julia documentation the other day. They do speed comparisons to other languages. Obviously R does not come out very well. The R code for quicksort is here and I noticed it was not vectorized at all. So I wondered if it could be improv...

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Guns are cool – Regions

August 10, 2014
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Guns are cool – Regions

This was supposed to be a post in which General Social Surveys (GSS) data were used to understand a bit more about the causation of differences between states. Thus it was to give additioanl insight than my previous post; Guns are Cool - Differenc...

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Guns are Cool – Differences between states

August 3, 2014
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Guns are Cool – Differences between states

Last week my blog showed that there are differences between states in the shootingtracker database. This week it is attempted to understand why states are different. A number of variables were extracted from a few sources, among which gun laws, % ...

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Guns are Cool – States

July 26, 2014
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Guns are Cool – States

Last week I looked at time effects of the shootingtracker database. This week I will look at the states. Some (smaller) states never made it on the database. Other states, far too frequently. The worst of these California. After correcting for populati...

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