Leipzig R Statistical Computing is the sixth local R user group in Germany, and has been holding meetings since February. In the next meeting on July 12, member Claudia Beleites will talk about her pacakges softclassval (for classifier performance measures) and hyperspec (for hyperspectral data). meetup.com: Leipzig R Statistical Computing
Monthly Archives: July 2012
Validating email adresses in R
I currently program an automated report generation in R – participants fill out a questionnaire, and they receive a nicely formatted pdf with their personality profile. I use knitr, LaTex, and the sendmailR package. Some participants did not provide valid email addresses, which caused the sendmail function to crash. Therefore I wanted some validation of
A tiny RCurl headache ;)
As more and more data go online (plus we love Google Drive) we are forced to connect to our data over the net. We mostly do this via RCurl (but we could do this using RGoogleDocs as well).In that case all that is required to get the data into R is the two lines of ...read more
A new open journal on Data Science
Springer has introduced a new open, peer-reviewed journal focused on Data Science: EPJ Data Science. What makes this a Data Science journal is novel uses of statistics, data analysis, computer techniques and public data sources to research a topic in another domain, rather than methodological research. Here are a few examples of the papers you'll find in the journal:...
Alternative to Monte Carlo Testing
When we backtest a strategy on a portfolio, it is a simple analysis of a single period in time. There are ways to “stress test” a strategy such as monte carlo, random portfolios, or shuffling the returns in a random order. I could never really wrap my head around monte carlo and shuffling the returns … Continue reading...
Three Questions about a Matrix of Coefficient Plots
It's Independence Day in the U.S., so I am taking the day off, but I received the following request for advice and thought I'd pass it along to my readers. I wonder if you could help – I am trying to create 9 different coefficient plots , which repr...
A tutorial on outlier detection techniques
by Yanchang Zhao, RDataMining.com There is an excellent tutorial on outlier detection techniques, presented by Hans-Peter Kriegel et al. at ACM SIGKDD 2010. It presents many popular outlier detection algorithms, most of which were published between mid 1990s and 2010, … Continue reading →
The Higgs boson: 5-sigma and the concept of p-values
Why are physicists talking about 5-sigma, and what's it got to do with statistics? In this short post I'll explain what 5-sigma is and why it's not a measure of how certain scientist are that they've found the Higgs boson
Glmnet_1.8 uploaded to CRAN
(by Trevor Hastie) Glmnet_1.8 uploaded to CRAN – This is a major revision, with two additional models included. 1) Multiresponse regression – family=”mgaussian” Here we have a matrix of M responses, and we fit a series of linear models in parallel. We use a group-lasso penalty on the set of M coefficients for each variable. This means they are...
To the Basics: Bayesian Inference on A Binomial Proportion
Think of something observable - countable - that you care about with only one outcome or another. It could be the votes cast in a two-way election in your town, or the free throw shots the center on your favorite...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
