This is a ‘do over’ of a project I started while at my former employer in the fall of 2012. I presented part 1 of this
framework at the FX Invest West Coast conference on September 11, 2012. I have made some changes and expanded the
analysis since then. Part 2 is complete and will follow this post in the week...
Tree methods such as CART (classification and regression trees) can be used as alternatives to logistic regression. It is a way that can be used to show the probability of being in any hierarchical group. The following is a compilation of many of the key R packages that cover trees and forests. The goal here
I am applying for Google Summer of Code 2013 with this “Biodiversity Visualizations using R” proposal. I am posting this idea to get feedback and suggestions from Biodiversity Informatics community. 
I was trying to change few levels in my factor variable by simply coercing characters on that factor variable but it dint seem to work.
data(iris)
iris$Species <- rep("Random", 71)
## Warning: invalid factor level, NAs generated
iris$Species
## setosa ...
First, I would like to welcome all of you reading this via R-Bloggers. I have been a user of this superb resource for years and I'm proud that I now have the opportunity to contribute!In The Financial Crisis on Tape Part I I demonst...
This is an overview of tools for speeding up your R code that I wrote for the Davis R Users’ Group.
It’s customary to quote Donald Knuth at this point, but instead I’ll quote my twitter buddy Ted Hart to illustrate a point:
I’m just going to say it.I like for loops in #Rstats,...
by Joseph Rickert Baseball fans have been serious about statistics since Carl Pearson was a young man (although I doubt that Carl followed the game). It is not clear, though, exactly when baseball statisticians moved from doing descriptive stats into predictive analytics. In his book Super Crunchers, Ian Ayers credits Bill James of Baseball Abstract fame for getting this...
Several R packages provide an interface to query map services (Google Maps, Stamen Maps or OpenStreetMap) to obtain raster images …
I’m a big fan of open-source software for research. For example, R-statistics, Qgis, and Grass GIS are awesome programs. R can do any statistical tests and numerical modeling you can imagine; if there’s not a built-in function you can write … Continue reading →
For some cryptic reason I needed a function that calculates function values on sliding windows of a vector. Googling around soon brought me to ‘rollapply’, which when I tested it seems to be a very versatile function. However, I wanted to code my own version just for vector purposes in the hope that it may 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
