# Monthly Archives: November 2010

## Life Is Short, Use Python

November 24, 2010
By

Life is short, use PythonI started to play with Python two weeks ago due to the limitation of R in terms of handling large data, then a friend of mine suggested me to try Python since I had to do data massage frequently, "Python is the best choice, trust me", he said. Although I was unwilling to learn another...

## The joys of teaching R

November 23, 2010
By

Just read a funny but much to the point blog entry on the difficulties of teaching proper programming skills to first year students! I will certainly make use of the style file as grading 180 exams is indeed a recurrent nightmare… Filed under: R,...

## Great-circle distance calculations in R

November 23, 2010
By

Recently I found myself needing to calculate the distance between a large number of longitude and latitude locations. As it turns out, because the earth is a three-dimensional object, you cannot simply pretend that you are in Flatland, albeit some … Continue reading →

## Principal Component Analysis: Which variables contribute most to principal components ?

November 23, 2010
By

Principal component analysis (PCA) is a mathematical transformation of possibly(correlated) variables into a number of uncorrelated variables called principal components. The resulting components from this transformation is defined in such a way that t...

## Slides from first Utah.edu & R.P. RUG meeting

November 23, 2010
By

Here are the slides from the first University of Utah and Research Park R Users Group meeting. They discuss getting help and finding packages. R

## How to make beautiful bubble charts with R

November 23, 2010
By

Nathan Yau has just published at FlowingData a step-by-step guide on making bubble charts in R. It's actually pretty simple: read in data, sqrt-transform the "bubble" variable (to scale the bubbles by area, not radius), and use the symbols function to plot. It's the last step, though, that really ups the presentation quality: read R's PDF file into Illustrator...

## R and AOL in NYC

November 23, 2010
By

R and the NYC R User Group get brief mentions in this article about AOL's offices in New York City. The NYC UseRs meet at AOL and (ironically) the next meeting on Dec 9 is on the topic of R at Google. New York Observer: Bringing Some Sizzle to the Dial-Up King (via)

## R Style Guide

November 23, 2010
By

Each year I have the pleasure (actually it’s quite fun) of teaching R programming to first year mathematics and statistics students. The vast majority of these students have no experience of programming, yet think they are good with computers because they use facebook! The class has around 100 students, and there are eight practicals. In

## Programming with R – Processing Football League Data Part I

November 23, 2010
By

In this post we will make use of football results data from the football-data.co.uk website to demonstrate creating functions in R to automate a series of standard operations that would be required for results data from various leagues and divisions. The first step is to consider what control options should be available as part of the

## Robust adaptive Metropolis algorithm [arXiv:10114381]

November 23, 2010
By

Matti Vihola has posted a new paper on arXiv about adaptive (random walk) Metropolis-Hastings algorithms. The update in the (lower diagonal) scale matrix is where is the current acceptance probability and the target acceptance rate; is the current random noise for the proposal, ; is a step size sequence decaying to zero. The spirit of