Recently I was in need of testing a mean vector. I wrote a few lines of code in R and had it done perfectly. Hotelling test is one of the least interesting test to me. never really figured out why… At that time I had some time to search more ... [Read more...]
Opta agreed to let the UK Guardian Data Blog publish 2010 World Cup Team and Player statistics. The data is available in a Google Docs spreadsheet. There are two tabs on this spreadsheet - one is PLAYERS the other is TEAM st...
Dear list, I brought up this issue before but a good solution never arised: being able to use screen on a remote server (so if something goes wrong on my side I can always resume that R session) inside of emacs in order to utilize ESS. The closest thing I ... [Read more...]
I see many economy indicator graphs that show emphasis by shading in the curve under the area (while x-axis is time). The shade is stronger at higher values (example). I did this in R below (ggplot2). This was a little more difficult that I’d expected. The color gradients are ... [Read more...]
Still drudging along preparing the new edition of Bayesian Core. I am almost done with the normal chapter, where I also changed the Monte Carlo section to include specific tools (bridge) for evidence/Bayes factor approximation. Jean-Michel has now moved to the new hierarchical model chapter and analysed longitudinal datasets ...
The UK Guardian Data Blog has great visualizations on the topics of the day - along with with specific references to data sets and online resources in use. You can find out more about the origins and plans of this and related data sites in t...
I've uploaded version 0.2-1 of my bibtex package to CRAN.
This release anticipates changes in R 2.12.0, and structures bibtex entries in object of the new class bibentry. The release also fixes various parser and lexer bugs [Read more...]
When writing a presentation we might want to use a bullet list to highlight some key points that might be lost if they are part of a large body of text. We can use the standard LaTeX environments for creating lists within a beamer presentation in a straightforward way.
Fast ...
Now that the 2010 survey is over, you might be wondering what we can learn from the data when the aggregated results are published. For a good guide to the kinds of questions you'll be able to answer, take a look at StatJump, where you can see tables and charts of ... [Read more...]
If you have not done so already, make sure you have R and Oracle setup as described in the previous article. If so, you should be able to create a connection from R and list the tables that are available in the HR schema.library('RODBC')ch
I have recently finished reading the sixth edition of The Analysis of Time Series: An Introduction by Chatfield in our Statistics reading group. Whilst enjoying most of the book I got a little confused when looking at Appendix D: Some … Continue reading →
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Andrew Gelman wrote today about some erroneous U.S. Governor approval ratings, noting that the ratings for Janet Napolitano sum to 108%. In fact most of these ratings do not sum to 100%. I prepared a clean CSV file of the ratings, making use of R‘s XML library and the readHTMLTable ... [Read more...]
Couple of weeks ago, I was looking for interesting data sets to play with using R. I came across this post and got inspired to use World Bank data to extract interesting patterns/facts about developing countries. World Bank has 300+ World Development i...
In math and economics, there is a long, proud history of placing imaginary prisoners into nasty, complicated scenarios. We have, of course, the classic Prisoner’s Dilemma, as well as 100 prisoners and a light bulb. Add to that list the focus of this post, 100 prisoners and 100 boxes. In this game, ...
At the moment I’m working on the implementation of full block designs (e.g., every member of group A rates each member from group and vice versa. A typical example is speed dating: every man rates each woman and vice versa). These designs can be analyzed with mixed effect ... [Read more...]
We are making slow progress on the normal and regression chapters as we decided to write the package at the same time we revise the chapters… Jean-Michel transformed the variable selection and model choice R codes of the regression chapter into generic functions that will fit within the package. I ...
Here's an interesting competition that may well lend itself to R: the IEEE International Conference on Data Mining is running a contest to find the best way of predicting traffic problems. There are three separate contests: Predicting congestion: a series of measurements from 10 selected road segments is given and the ... [Read more...]