On July 25th, I’ll be presenting at the Seattle R Meetup about implementing Bayesian nonparametrics in R. If you’re not sure what Bayesian nonparametric methods are, they’re a family of methods that allow you to fit traditional statistical models, such as mixture models or latent factor models, without having to fully specify the number of
The strategies used in Strategy Diversification in R were labeled as Strategy1 and Strategy2. Strategy1 Indicator: 52 week Simple Moving Average Entry Rule: Buy 1000 shares when price crosses and closes above 52 week Simple Moving Average Exit Rule: Exit all positions when prices crosses and closes below 52 week Simple Moving Average Classification: Long … Continue reading...
A bug-fix release 0.9.12 of Rcpp arrived earlier today on CRAN and is now in Debian too. This fixes a minor snafu with the Rcpp::Enviroment constructor following a minor change made for 0.9.11. It also reduces the number of unit tests running by de...
Here’s one purely for fun – a wordcloud built from the Supreme Court’s opinion on Arizona et al. v United States. Word clouds, though certainly not the most scientific of visualization techniques, are often engaging and “fun” ways to lead…
Two new local R user groups to report this week. In Turkey, the Ankara R Users Group has just started up. No meetings are scheduled yet, so be sure to suggest a meeting time/location when you sign up. The Toronto-based R Matlab Users group focuses on financial services applications. Created by Bryan Downing (who also produces the QuantLabs blog),...
I continue with the practicing with ChemSpec, and this time I import seven spectra of olive oil. This time I have been more careful and I have the frequency column as numeric form the CSV file. Once I have the spectra (with and offset):Take in account ...
Referring to a recent posting on r-sig-eco mailing list I'll add this example to theBioBucket:library(vegan)library(vegan)data(dune)sol <- metaMDS(dune) # use ordipointlabel -# here is an example where I added cex according to species frequencies:pl...
An easy one today, but something that stumped me for a while* the first time I tried it out. How do you get a group mean (or other summary statistic) from R? Lets say you have a Y variable that represents repetitions for each of however many factors. You could subset the data by each 
The assumption of equal variances among the groups in analysis of variance is an expression of the assumption of homoscedasticity for linear models more generally. For ANOVA, this assumption can be tested via Levene's test. The test is a function of the residuals and means within each group, though various modifications are used, including the Brown-Forsythe...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
