Monthly Archives: September 2012

Research support specialist position at Ryerson University

September 3, 2012
By

The Ted Rogers School of Management at Ryerson University in Toronto has an opening for a research support specialist to assist with monitoring current research projects and to provide assistance with econometric/statistical analysis and training.Requi...

Read more »

Installing RStan in Ubuntu

September 3, 2012
By

Based on RStan Getting StartedR packagesAssuming you have the most up to date version of R, the following packages need to be installed. This assumes you have the c2d4u PPA available. See here for more information.sudo apt-get install r-cran-...

Read more »

Project Euler — problem 19

September 3, 2012
By

I’ve been working overtime last weekend. Although I suffered little from the Monday syndrome, I still need a break. So, I’m back to the Project Euler after days of Olympic data digging. Today, I’m gonna to solve the 19th problem. You are given the following … Continue reading →

Read more »

A look at Bayesian statistics

September 3, 2012
By
A look at Bayesian statistics

An introduction to Bayesian analysis and why you might care. Fight club The subject of statistics is about how to learn.  Given that it is about the unknown, it shouldn’t be surprising that there are deep differences of opinion on how to go about doing it (in spite of the stereotype that statisticians are accountants … Continue reading...

Read more »

Fixing non positive definite correlation matrices using R

September 3, 2012
By

ProblemWhen a correlation or covariance matrix is not positive definite (i.e., in instances when some or all eigenvalues are negative), a cholesky decomposition cannot be performed. Sometimes, these eigenvalues are very small negative numbers and occ...

Read more »

Descriptive statistics of some Agile feature characteristics

September 2, 2012
By
Descriptive statistics of some Agile feature characteristics

The purpose of software engineering research is to figure out how software development works so that the software industry can improve its quality/timeliness (i.e., lower costs and improved customer satisfaction). Research is hampered by the fact that companies are not usually willing to make public good quality data about the details of their software development

Read more »

Faster creation of binomial matrices

September 2, 2012
By

Scott Chamberlain blogged about faster creation of binomial matrices the other day, and even referred to our RcppArmadillo package as a possible solution (though claiming he didn't get it to work, tst tst -- that is what the rcpp-devel list is here to help with).The post also fell short of a good aggregated timing comparison for which we love...

Read more »

Stan

September 2, 2012
By
Stan

Andrew Gelman has announced the release of Stan version 1.0.0 and its R interface RStan.  Stan – named after Stanislaw Ulam, the inventor of the Monte Carlo method – is a new MCMC program that represents a major technological leap … Continue reading →

Read more »

Call for contribution: the RDataMining package – an R package for data mining

September 2, 2012
By
Call for contribution: the RDataMining package – an R package for data mining

Join the RDataMining project to build a comprehensive R package for data mining http://www.rdatamining.com/package We have started the RDataMining project on R-Forge to build an R package for data mining. The package will provide various functionalities for data mining, with … Continue reading →

Read more »

Discrete colors in ggplot

September 1, 2012
By
Discrete colors in ggplot

Have you ever wanted an easy way to generate continuous color pallettes for a discrete factor? I came across a question over on Stackoverflow about how add color to a ggplot figure. I often find myself with lot’s of categories that are discrete when I want a continuous color plot. This can be achieved by writing a quick...

Read more »