Monthly Archives: February 2012

XYZ geographic data interpolation, part 2

February 29, 2012
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XYZ geographic data interpolation, part 2

Having recently received a comment on a post regarding geographic xyz data interpolation, I decided to return to my original "xyz.map" function and open it up for easier interpretation. This should make the method easier to adapt and follow.The above graph shows the distance to Mecca as interpolated from 1000 randomly generated lat/lon...

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A minimum variance portfolio in 2011

February 29, 2012
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A minimum variance portfolio in 2011

2011 was a good vintage for minimum variance, at least among stocks in the S&P 500. Previously The post “Realized efficient frontiers” included, of course, a minimum variance portfolio.  That portfolio seemed interesting enough to explore some more. “What does ‘passive investing’ really mean” suggests that minimum variance should be considered a form of passive … Continue reading...

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Custom Amazon EC2 config for Rstudio

February 29, 2012
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IntroductionThis post is a work in progress building on the previous post. It's my attempt to simultaneously learn Amazon's AWS tools and set up R and Rstudio Server on a customized "cloud" instance. I look forward to testing some R jobs that have la...

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Expanding Visualization of published system edges (R)

February 28, 2012
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Expanding Visualization of published system edges (R)

I happened to be looking over a revised text of a systems author I happen to follow. I will be a bit vague about specifics, as the system itself is based on well know ideas, but I'll leave the reader to research related systems.  The basic message...

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Parsing R code: Freedom of expression is not always a good idea

February 28, 2012
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Parsing R code: Freedom of expression is not always a good idea

With my growing interest in R it was inevitable that I would end up writing a parser for it. The fact that the language is relatively small (the add-on packages do the serious work) hastened the event because it did not look like much work; famous last words. I knew about R’s design and implementation

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Webinar tomorrow: Big-data statistics with Revolution R with IBM Netezza

February 28, 2012
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As explained in detail by Michele Chambers at the IBM Netezza blog, there are two keys to getting fast performance with statistical analysis on massive data sets with R: Massive parallelization: break the problem down into small pieces, and run them in parallel Bring the R engine to the data (not the other way around), to avoid data transfer...

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PCA for NIR Spectra_part 006: "Mahalanobis"

February 28, 2012
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PCA for NIR Spectra_part 006: "Mahalanobis"

Outliers have an important influence over the PCs, for this reason they must be detected and examinee.We have just the spectra without lab data, and we have to check if any of the sample spectra is an outlier ( a noisy spectrum, a sample which belongs ...

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People voice about Lynas Malaysia through Twitter Analysis with R CloudStat

February 28, 2012
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People voice about Lynas Malaysia through Twitter Analysis with R CloudStat

People voice about Lynas Malaysia through Twitter Analysis with R CloudStat: CloudStat Analysis: This is a twitter analysis report for “Lynas” from 21 till 28 February 2012, generated by CloudStat Twitter Application. Lynas was a hot topic, espec...

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useR! 2012 Early Registration Ending Tomorrow!

February 28, 2012
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useR! 2012 Early Registration Ending Tomorrow!

The early registration deadline for useR! 2012 is tomorrow! Visit the Online Registration Website. The fees for registration increase March 1st.

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Apprentice Piece with Lattice Graphs

February 28, 2012
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Apprentice Piece with Lattice Graphs

Lattice graphs can be quite tedious. I don't use them too often and  when I need them I usually have to dig the archives for the parameter-details.The here presented example may serve as a welcome template for the usage of panel functions, panel o...

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