The TimeSeriesIreland Blog posted an excellent start on a function that automatically computes marginal effects for probit and logit models. As I have always wanted an easy-to-use function that computes and reports marginal effects in R, I was elated ...
It is possible to show that the square root of two can be expressed as an infinite continued fraction. √ 2 = 1 + 1/(2 + 1/(2 + 1/(2 + … ))) = 1.414213… By expanding this for the first four iterations, we get: Read More: 547 Words Totally
Hadley Wickham, the Rice professor and prolific R hacker best known as the author of the ggplot2 graphics package, will be coming to San Francisco June 8-9 to deliver his new R Development Master Class (in conjunction with Revolution Analytics). This course will build on the skills of basic R programmers with instruction in advanced R programming techniques, development...
Pete Warden's Data Science Toolkit (which we mentioned briefly last week) is an open-source information server that provides an API you can query for information useful for building data science applications, like identifying proper names in unstructured text, or converting IP addresses to lat/long coordinates. You can make queries via the Web interface or by direct interface to the...
![Stata-like Marginal Effects for Logit and Probit Models in R [2]](http://feeds.wordpress.com/1.0/comments/timeseriesireland.wordpress.com/640/)
My thanks to those who emailed comments and suggestions for my ‘mfx’ function, I’m happy that I could fill a void for some people. I also received a request/suggestion from Tony Cookson, along with a helpful fix for a bug in the code, to include an option that would allow the user to specify values 
Although this blog’s primary focus is time series, one feature I missed from Stata was the simple marginal effects command, ‘mfx compute’, for cross-sectional work, and I could not find an adequate replacement in R. To bridge this gap, I’ve written a (rather messy) R function to produce marginal effects readout for logit and probit 
The following script allows you to simulate sample runs of Win, Loss, Breakeven streaks based on a random distribution, using the run length encoding function, rle in R. Associated probabilities are entered as a vector argument in the sample function.Y...
![A survey of the [60′s] Monte Carlo methods [2]](http://xianblog.files.wordpress.com/2011/05/img_8168-e1305488888661.jpg?w=315&h=344)
The 24 questions asked by John Halton in the conclusion of his 1970 survey are Can we obtain a theory of convergence for random variables taking values in Fréchet spaces? Can the study of Monte Carlo estimates in separable Fréchet spaces give a theory of global approximation? When sampling functions, what constitutes a representative sample 
I wrote a simple function for plotting a phylogeny in ggplot2. However, it only handles a 3 species tree right now, as I haven't figured out how to generalize the approach to N species.Any ideas on how to improve this?
My TreeBASE R package is essentially functional now. Here’s a quick tutorial on the kinds of things it can do. Grab the treebase package here, install and load the library into R. TreeBASE provides two APIs to query the database, one which searches by the metadata associated with different publications (called OAI-PMH), and another which
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
