Monthly Archives: May 2009

Temporary Debian mail outage

It would appear that debian.org rejected mail for maybe up to twelve hours from late yesterday afternoon (Central timezone) to some time shortly after I got up this morning. Things appear to be back to normal, so a big Thanks to the mail admins. If you happened to have sent me mail to my debian.org address during that time period, you may have...

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Data.gov

May 21, 2009
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Data.gov

I am always on the lookout for useful data sources for training in statistics, so I am excited that Data.gov has opened for business. The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the US Government.

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Data.gov

May 21, 2009
By
Data.gov

I am always on the lookout for useful data sources for training in statistics, so I am excited that Data.gov has opened for business. The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the US Government.

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Bootstrapping and the boot package in R

May 21, 2009
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Bootstrapping and the boot package in R

I was recently asked about options for bootstrapping. The following post sets out some applications of bootstrapping and strategies for implementing it in R.I've found bootstrapping useful in several settings:where the statistic I'm interested in is a ...

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Baby steps with RSRuby in Rails

May 20, 2009
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Baby steps with RSRuby in Rails

Plotting and charting libraries for Ruby (on Rails) abound. However, few are sophisticated enough for scientists and many are not actively maintained. Plotting in R, on the other hand, is about as sophisticated as it comes. Can we bridge Ruby and R? Yes we can, thanks to Alex Gutteridge’s RSRuby. The next

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Create multiple graphics in R without multiple calls to pdf / postscript / jpeg / png

May 14, 2009
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To save multiple graphics, e.g, Rplot001.pdf, Rplot002.pdf, …, Rplot050.pdf, we don’t have to call pdf() 50 times (or any similar function). Use “Rplot%03d.pdf” for filename in pdf() and each plot() call will be saved to a new pdf file. Use dev.off() once at the end to close all devices! check out ?sprintf for more information

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Nonparametric High-Dimensional Time Series Analysis

Functional Gradient Descent (FGD) is a method of nonparametric time series analysis, useful in particular for estimating conditional mean, variances and covariances for very high-dimensional time series. FGD is a kind of hybrid of nonparametric statis...

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Negative Scalability Coefficients in Excel

May 12, 2009
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Negative Scalability Coefficients in Excel

Recently, several performance engineers, who have been applying my universal scalability law (USL) to their throughput measurements, reported a problem whereby their Excel spreadsheet calculations produced a negative value for the coherency parameter (...

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Packages featured with Inference for R

May 12, 2009
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Packages featured with Inference for R

quantmod, TTR, and xts were (not so) recently featured on the Inference for R Blog. Inference for R is a Integrated Development Environment (IDE) designed specifically for R.The post gives an example of how to easily perform advanced financial stock a...

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Analytic Infrastructure – Three Trends

May 11, 2009
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This is a post about systems, applications, services and architectures for building and deploying analytics. Sometimes this is called analytic infrastructure. In this post, we look at several trends impacting analytic infrastructure. Trend 1. Open source analytics has reached Main Street. R, which was first released in 1996, is now

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