Publications by Wingfeet
JAGS model Fe concentration in rainwater including values below detection level
In my previous post I ignored the fact that some data are below the detection level. I would not know how to handle those in a mixed model from lme4 or nlme. However, JAGS can handle these values. Next to that I kept the usual independent variables, such as random effects for location, machine etc.DataData has been acquired and proces...
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Fukushima region radiation decrease
Fukushima is still a topic which gets headlines, and somewhere in a comment was a link to actual and historical radiation data: Fukushima prefecture radioactivity measurement map. It takes a bit of time to load but then you have a map of the Fukushima region with current radiation levels at measurement stations. Somewhere on that w...
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plotting y and log(y) in one figure
Sometimes I have the desire to plot both on the linear and on the log scale. To save space just two figures is not my solution. I want to reuse the x-axis, legend, title. This post examines possibilities to do so with standard plot tools, lattice and ggplot2.DataData is completely artificial.library(ggplot2)library(lattice)datastart �...
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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 Jags for quite some time because I had the (incorrect) impression openBugs developmen...
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Le Monde puzzle 847 in Julia
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 [1]: function lemonde847(xx) a=[xx[1],2] b=[xx[2],8] c=[xx[3],4] sum(kron(c,kron(...
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Converting a JAGS model to STAN
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 before. The only difference is that by now I am reading the data using read.xls from ...
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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 Windows, for Mac there are only older versions of Engauge.I tried these programs on...
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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 can run on Mac, Windows and Linux. WebPlotDigitizer is, as one might guess, web b...
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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 the model I want a bit more. Hence a fresh start.DataData is the chocolate data fro...
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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 pointed to influence of Procrustes and STATIS in these models, I probably should have mentioned Per Br...
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