2128 search results for "Twitter"

New blog from Rmetrics Foundation

June 21, 2010
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The Rmetrics Foundation (the sharp minds behind the Rmetrics suite of packages for financial analysis in R) have just launched a new blog where you can keep up with the latest Rmetrics news. Amongst the recent news: a ne eBook about data management of Indian financial market data, and a new interface between Rmetrics and AMPL. You can also...

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Do Not Log-Transform Count Data, Bitches!

June 17, 2010
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Do Not Log-Transform Count Data, Bitches!

OK, so, the title of this article is actually Do not log-transform count data, but, as @ascidacea mentioned, you just can’t resist adding the “bitches” to the end. Onwards. If you’re like me, when you learned experimental stats, you were taught to worship at the throne of the Normal Distribution. Always check your data and

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Conferenza a Padova

June 16, 2010
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Conferenza a Padova

Today and tomorrow, I am attending the annual Italian statistical society meeting. While I appreciate very much the invitation, as well as the opportunity to walk through  Padova and Venezia for a short (and alas rainy!) hour on the way there (leaving home at 8am, walking in Venezia at noon!), I am rather skeptical of

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plagiarism exposed!

June 14, 2010
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plagiarism exposed!

Last morn, I had the surprise of receiving the following email: This is to inform you that the following abstract has been submitted to the 3rd International Conference of the ERCIM WG on COMPUTING & STATISTICS (ERCIM’10) Ab#: 114 Title: Goodness of Fit Via Mixtures of Beta distributions Keywords: nonparametric estimation, posterior conditional predictive p-value.

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In case you missed it: May Roundup

June 14, 2010
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In case you missed them, here are some articles from last month of particular interest to R users. We linked to 13 videos for learning R, from the basics ("What is R?") to more advanced topics. We noted the release of R 2.11.1. We announced that Revolution Analytics makes its software available free of charge to the academic community....

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bug in schoolmath

June 13, 2010
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bug in schoolmath

Neil Gunther has pointed out on his blog that the prime number decomposition R package schoolmath contains mistakes in the function primes, listing 1 as a prime number but also including decomposable numbers like 133 in its list of prime numbers: > primes(100,140) 101 107 111 113 123 129 131 137 > primes(50,140)  

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R Tools for Dynamical Systems ~ bifurcation plot in R for system of ODEs

June 12, 2010
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R Tools for Dynamical Systems ~ bifurcation plot in R for system of ODEs

As per request, here is the code that I wrote to draw bifurcation plots in R. Bifurcation diagrams for discrete maps can be done using this code by James Jones. It is a little easier since approximation is not needed. In the following code, I used the deSolve library to draw bifurcation diagrams for a

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Thoughts on Making Data Work

June 9, 2010
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I really enjoyed all four talks at today's online conference, Making Data Work. (Disclosure: Revolution sponsored this conference.) I thought the four speakers together gave a great overview of issues related to the processing, analysis, and visualization of big data. Mike Driscoll started off with a useful categorization for data size. "Small Data" (<10Gb) fits in the memory of...

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Pegging your multicore CPU in Revolution R, Good and Bad

June 9, 2010
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Pegging your multicore CPU in Revolution R, Good and Bad

I take an almost unhealthy pleasure in pushing my computer to its limits. This has become easier with Revolution R and its free license for academic use. One of its best features is debugger that allows you to step through … Continue reading →

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Stratified sampling

June 9, 2010
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Stratified sampling

The recently arXived paper of Goldstein, Rinott and Scarsini studies the impact of refining a partition on the precision of a stratified maximising/integration Monte Carlo approach. Quite naturally, if the partition gets improved, simulating points in each set of the partition can only improve the quality of the approximation, whether the problem is in maximising

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