Monthly Archives: February 2009

R: Good practice – adding footnotes to graphics

February 17, 2009
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R: Good practice – adding footnotes to graphics

In some statistical programs there is the option available to attach a footnote to the graphical output that is created. This footnote may contain the name of the script or the file that produced the graphic, the author’s name and the date of creation. In SAS for example there is a footnote command to achieve

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Pearson vs. Spearman Correlation Coefficients

February 17, 2009
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Pearson vs. Spearman Correlation Coefficients

One of the misuses of statistical terminology that annoys me most is the use of the word “correlation” to describe any variable that increases as another variable increases. This monotonic trend seems worth looking for, but it plainly is not what m...

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TTR_0.2 on CRAN

February 15, 2009
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TTR_0.2 on CRAN

I am happy to announce a long-overdue update to the TTR package (version 0.2) is now on CRAN.This update represents a major milestone, as TTR useRs are no longer restricted to using matrix objects. TTR 0.2 uses xts internally, so all major time series...

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Single Letter Frequencies in English

February 15, 2009
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Single Letter Frequencies in English

Every time that I read a paper that discusses the frequencies of single letters in English, I feel like I should sit down and calculate them for myself from a sample of English text. Today, I finally did. Here are the probabilities and negative log pro...

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R in SAS

February 15, 2009
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R in SAS

Another "proof" that R definitely is one of mainstream statistical packages is the news that SAS will provide an interface to R via SAS/IML Studio (today known as SAS Stat Studio).

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R-Sessions 32: Forward.lmer: Basic stepwise function for mixed effects in R

February 13, 2009
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Intended to be a customized solution, it may have grown to be a little more. forward.lmer is an early installment of a full stepwise function for mixed effects regression models in R-Project. I may put in some work to extend it, or I may not. Neverthel...

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New project: RInside

February 12, 2009
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A few days ago, I started a new project called RInside by uploading a few files to a new SVN repo at R-Forge. RInside makes it easy to embed R into your own C++ application by hiding the nitty gritty of initializing an R interpreter behind a simple abstraction. More information is at a (currently pretty simple) RInside...

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Fitting Legendre (orthogonal) polynomials in R

February 10, 2009
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Fitting Legendre (orthogonal) polynomials in R

Frederick Novomestky packaged a series of orthogonal polynomials in the orthopolynom R package. However, his functions can not be used "directly" in a statistical model, say in lm(). There is no need to use functions from orthopolynom package, since th...

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Positioning charts with fig and fin

February 9, 2009
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Positioning charts with fig and fin

R offers several ways to spatially orient multiple graphs in a single graphing space. The layout() function and mfrow/mfcol parameter settings are adequate solutions for many tasks and allow the graphing space to be broken up into tabular or matrix-based arrangements. For more fine grained manipulation, the fig and fin parameter settings are available. This The post Positioning...

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Positioning charts with fig and fin

February 9, 2009
By

R offers several ways to spatially orient multiple graphs in a single graphing space. The layout() function and mfrow/mfcol parameter settings are adequate solutions for many tasks and allow the graphing space to be broken up into tabular or matrix-ba...

Read more »