Blog Archives

Simple Pharmacokinetics with Jags

March 2, 2014
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Simple Pharmacokinetics with Jags

In this post I want to analyze a first order pharmocokinetcs problem: the data of study problem 9, chapter 3 of Rowland and Tozer (Clinical pharmacokinetics and pharmacodynamics, 4th edition) with Jags. It is a surprising simple set of data, but still there is enough to play around with.Data, model and analysisThe data is simple enough. One subject's concentration...

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Unemployment revisited

February 23, 2014
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Unemployment revisited

Approximately a year ago I made a post graphing unemployment in Europe and other locations. I have always wanted to do this again, not because the R-code would be so interesting, but just because I wanted to see the plots. As time progressed I attempte...

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Bayesian analysis of sensory profiling data III

February 16, 2014
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Bayesian analysis of sensory profiling data III

Last week I extended my Bayesian model. So this week I wanted to test it with different data. There is one other data set with profiling data in R, french fries in the reshape package. 'This data was collected from a sensory experiment conducted at Iow...

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Bayesian analysis of sensory profiling data, part 2

February 9, 2014
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Bayesian analysis of sensory profiling data, part 2

Last week I made the core of a Bayesian model for sensory profiling data. This week the extras need to be added. That is, there are a bunch of extra interactions and the error is dependent on panelists and descriptors.Note that where last week I pointe...

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Bayesian analysis of sensory profiling data

February 2, 2014
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Bayesian analysis of sensory profiling data

I looked at Bayesian analysis of sensory profiling data in May and June 2012. I do remember not being totally happy with the result and computations taking a bit more time than I wanted. But now it is 2014, I can use STAN and I have been thinking about...

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Converting plots to data II

January 26, 2014
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Converting plots to data II

There were quite some reactions on lasts week's post converting plots to data. Two additional programs were mentioned; WebPlotDigitzier and DataThief. Note that google or wikipedia has a bunch of alternatives. Datathief is shareware, a java program, so...

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Convering plots to data

January 18, 2014
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Convering plots to data

It is a problem which occurs ever so often in applied work, you have a plot, but you want the data. There are at least two programs which can help you there; PlotDigitizer and Engauge Digitizer. I got both on my openSuse machine. Both are available for...

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Converting a JAGS model to STAN

January 11, 2014
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For my first experience with STAN I wanted to convert my last JAGS program into STAN. This was a bit more difficult than I expected. The JAGS program was Fe concentration in rainwater including values below detection level.DataData has been explained b...

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Le Monde puzzle 847 in Julia

January 4, 2014
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This week I wanted to play around with Julia and exporting the results. I found http://xianblog.wordpress.com/2013/12/29/le-monde-puzzle-847/ to be just the right size to play around with. CodeA function to check if a triplet has the desired property In : function lemonde847(xx) a=,2] b=,8] c=,4] sum(kron(c,kron(a,b)))endOut:lemonde847 (generic function with 1 method)Just a check -...

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Sinterklaas and Santa Claus gave presents

December 27, 2013
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Sinterklaas and Santa Claus gave presents

In December my nice little netbook acquired a shiny new openSUSE 13.1, including all the goodies I might want to use in 2014; R, Stan, Julia and Jags. So here is what you might get when you set up a computer for statistics today.JagsI have been using J...

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