Posts Tagged ‘ statistics ’

Bayes on drugs (guest post)

May 20, 2012
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Bayes on drugs (guest post)

This post is written by Julien Cornebise. Last week in Aachen was the 3rd Edition of the Bayes(Pharma) workshop. Its specificity: half-and-half industry/academic participants and speakers, all in Pharmaceutical statistics, with a great care to welcome newcomers to Bayes, so as to spread as much as possible the love where it will actually be used.

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Births and week-ends, in France

May 19, 2012
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Births and week-ends, in France

This week, I have seen on the internet (sorry, I cannot find proper references) the graph produced here on the right: which birthday is most likely ? The fact that I have no further information is important, since I do not know in which country suc...

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In Mexico, more marriages ending in divorce, and sooner

May 18, 2012
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In Mexico, more marriages ending in divorce, and sooner

R user Diego Valle analyzed the rate of divorces in Mexican marriage since 1993 (the earliest date for which data are available) and found that not only have more marriages ended in divorce over time, but marriages that do end are ending sooner: This chart is a bit complicated, but it bears close inspection. Each line you see is...

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Non transitivity of correlation for random vectors in dimension 3

May 18, 2012
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Non transitivity of correlation for random vectors in dimension 3

Dependence in dimension 2 is difficult. But one has to admit that dimension 2 is way more simple than dimension 3 ! I recently rediscovered a nice paper, Langford, Schwertman & Owens (2001), on transitivity of the property of being positively c...

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Criticism 4 of NHST: No Mechanism for Producing Substantive Cumulative Knowledge

May 18, 2012
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In this fourth part of my series of criticisms of NHST, I’m going to focus on broad

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Exponential decay models

May 17, 2012
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Exponential decay models

All models are wrong, some models are more wrong than others. The streetlight model Exponential decay models are quite common.  But why? One reason a model might be popular is that it contains a reasonable approximation to the mechanism that generates the data.  That is seriously unlikely in this case. When it is dark and … Continue reading...

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garch() uncertainty

May 16, 2012
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garch() uncertainty

As part of an on-going paper with Kerrie Mengersen and Pierre Pudlo, we are using a GARCH(1,1) model as a target. Thus, the model is of the form which is a somehow puzzling object: the latent (variance) part is deterministic and can be reconstructed exactly given the series and the parameters. However, estimation is not

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Will 2015 be the Beginning of the End for SAS and SPSS?

May 15, 2012
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Will 2015 be the Beginning of the End for SAS and SPSS?

Learning to use a data analysis tool well takes significant effort, so people tend to continue using the tool they learned in college for much of their careers. As a result, the software used by professors and their students is … Continue reading →

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Blog aggregators

May 15, 2012
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A very useful way of keeping up with blogs in a particular area is to subscribe to a blog aggregator. These will syndicate posts from a large number of blogs and provide links back to the original sources. So you only need to subscribe once to get all the good stuff in that area. There are now several blog...

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generalised ratio of uniforms

May 14, 2012
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generalised ratio of uniforms

A recent arXiv posting of the paper “On the Generalized Ratio of Uniforms as a Combination of Transformed Rejection and Extended Inverse of Density Sampling” by Martino, Luengo, and Míguez from Madrid rekindled my interest in this rather peculiar simulation method. The ratio of uniforms samples uniformly on the subgraph to produce simulations from p

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