Monthly Archives: August 2011

Number of components in a mixture

August 5, 2011
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Number of components in a mixture

I got a paper (unavailable online) to referee about testing for the order (i.e. the number of components) of a normal mixture. Although this is an easily spelled problem, namely estimate k in I came to the conclusion that it is a kind of ill-posed problem. Without a clear definition of what a component is,

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Upcoming R training classes, live from the experts

August 5, 2011
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Revolution Analytics is hosting several hands-on R training classes over the next few months, with in-person instruction from two leading package authors and experts from the R community. Diethelm Würtz from ETH Zurich will give a two-day master class on Portfolio Selection and Optimization in Practice. Prof Würtz leads the Rmetrics project, and will provide in-depth instruction on using...

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R as a cure for ‘mindless statistics’?

August 5, 2011
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Several years ago Gerd Gigerenzer wrote: “Statistical rituals largely eliminate statistical thinking in the social sciences. Rituals are indispensable for identification with social groups, but they should be the subject rather than the procedure of science. Statistical rituals largely eliminate … Continue reading →

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Positive coefficient regression in R

August 5, 2011
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Positive coefficient regression in R

Ever have a regression model where the coefficients don't make sense? I've been trying to predict electricity and gas consumption from daily activity schedules but a simple linear regression kept saying that demands should go down the more an activity is performed. Fortunately I found the nnls package and show here how you can use it to...

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More on JSM

August 5, 2011
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While my time at the 2011 Joint Statistical Meetings was short--I unfortunately missed some presentations I would have like to have attended--it was a great experience. The collection of academics and professionals is very different from the other con...

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Image Data from ImageJ to R and Vice Versa

August 5, 2011
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In recent years many R packages have been developed to enable image analysis in R. As an alternative the combination of R with a powerful image analysis software like ImageJ offers many advanced image analysis interfaces and algorithms not yet available in R. Bio7 integrates both applications in a Rich Client Plattform based on Eclipse

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Outlier Detection with DPM Slides from JSM 2011

August 5, 2011
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Outlier Detection with DPM Slides from JSM 2011

Here are the 14 slides I used during my talk at the Joint Statistical Meetings 2011: shotwell-jsm-2011.pdf. I'm trying hard to minimize the text in my presentation slides. But, this usually requires that I practice more. Hence, you will know which talks I have practiced thoroughly by the amount of text in the slides .

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Friday Links: R, OpenHelix Bioinformatics Tips, 23andMe, Perl, Python, Next-Gen Sequencing

August 5, 2011
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Friday Links: R, OpenHelix Bioinformatics Tips, 23andMe, Perl, Python, Next-Gen Sequencing

I haven't posted much here recently, but here is a roundup of a few of the links I've shared on Twitter (@genetics_blog) over the last two weeks.Here is a nice tutorial on accessing high-throughput public data (from NCBI) using R and Bioconductor.Cloud...

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New Rcpp master classes scheduled for New York and San Francisco

August 4, 2011
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Together with Revolution Analytics, I will be offering two more one-day classes on the Rcpp package for seamless integration of R and C++.The format will follow the workshop Romain and I gave during the tutorial day preceding this year's R/Financ...

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Aug 4, 2011 "plunge" headlines are in the air tonight

August 4, 2011
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Aug 4, 2011 "plunge" headlines are in the air tonight

Today's financial headlines are littered with the word 'plunge.'  Considering today's (cl-cl) drop on the S&P500 was just about -5%, I don't know that I would exactly call that a plunge.         &nb...

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