I am not sure I have ever done a post like this, but I was so blown away I had to do this post simply to embed this amazing Youtube video from the author of the R packages rCharts and slidify. Watch this screencast as he creates d3/raphael charts...

I am not sure I have ever done a post like this, but I was so blown away I had to do this post simply to embed this amazing Youtube video from the author of the R packages rCharts and slidify. Watch this screencast as he creates d3/raphael charts...

This code has been kindly contributed by Robin Edwards

Since I’ve seen this beautiful color wheel visualizing the colors of Flickr images, I’ve been fascinated with large scale automated image analysis. At the German Market Research association’s conference in late April, I presented some analyses that went in the same direction (click to enlarge): On the image above you can see the color

I know I have already written a lot about technicalities in logistic regression (see for example: How robust is logistic regression? and Newton-Raphson can compute an average). But I just ran into a simple case where R‘s glm() implementation of logistic regression seems to fail without issuing a warning message. Yes the data is a Related posts:

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 current puzzle is as follows: Define the symmetric of an integer as the integer obtained by inverting the order of its digits, eg 4321 is the symmetric of 1234. What are the numbers for which the square is equal to the symmetric of the square of the symmetric? I first consulted stackexchange to find

R users know it can be finicky in its requirements and opaque in its error messages. The beginning R user often then happily discovers that a mailing list for dealing with R problems with a large and active user base, R-help, has existed since 1997. Then, the beginning R user wades into the waters, asks… Continue reading →

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

Every once in a while I encounter a problem that requires the use of calculus. This can be quite bothersome since my brain has refused over the years to retain any useful information related to calculus. Most of my formal training in the dark arts was completed in high school and has not been covered