Monthly Archives: September 2012
Fitting an ellipse to point data
An R-based Research Notebook – Test
The following are from Tom Torsney-Weir’s blog (here’s the repo).
- Simple MathJax and R example
- A more complex example with caching
- Another plotting example using
ggplot
- Example using
googleVis
Working with Bipartite/Affiliation Network Data in R
This is something I put together a long time ago and recently updated for use with larger data sets. Preliminaries Much of the material here is covered in the more comprehensive “Social Network Analysis Labs in R and SoNIA,” on which I … Continue reading →
Football, an ordinal model
On September 19th, flo2speak remarked under a post that his/her experience is that ordinal models had better performance. That seems reason enough to try, so there we are. In examining this type of model it is found that more complex models can be...
Plot R Data With googleVis
Here is a little code snippet that shows how to do two things
- Use the Google Maps API to resolve place names into lat-long coordinate pairs.
- Plot R dataframes that contain lat-long data (for example from #1) onto Google Maps for quick visualization using the googleVis package. The embedded map looks a little wonky here but it looks...
Quantifying student feedback using Org mode and R
As the term has progressed, my LSM2241 lectures are getting more consistent. I’m aiming to use 45 slides for what is officially a two hour lecture, although in reality it lasts about 90 minutes. We take a break at about 50 … Continue reading →
my Facebook social network
I got very excited on making a network diagram of my Facebook network using Ghefi (https://gephi.org/) and submitted my first assignment for the Social Network Analysis course on https://www.coursera.org/. It's middle of the night, so I will ...
Padding integers for use in filenames
If you’ve ever written code that generates a whole whack of files, you may have came across the following problem when processing them. Using a naming convention wherein files are numbered will gum up any ordering which is based on string sorting (ls, for example). What you end up with is something like this: Which 
Merging Dataframes by Partly Matching String
The latest posting by Tony Hirst sparked my attention because I was thinking about a very similar issue recently.
I was also fiddling around with agrep and adist until I realised that for this very issue matching of substrings is not as important as matching multiple words.. With this different approach I quite easily matched all but 3...
Weekend Reading – Gold in October
I recently came across the “An early Halloween for gold traders” article by Mark Hulbert. I have discussed this type of seasonality analysis in my presentation at R/Finance this year. It is very easy to run the seasonality analysis using the Systematic Investor Toolbox. This confirms that October have been historically bad for Gold, but 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
