Monthly Archives: August 2011

The Visual Difference – R and Anscombe’s Quartet

August 30, 2011
By
The Visual Difference – R and Anscombe’s Quartet

I spent a chunk of today trying to get my thoughts in order for a keynote presentation at next week’s The Difference that Makes a Difference conference. The theme of my talk will be on how visualisations can be used to discover structure and pattern in data, and as in many or my other recent

Read more »

Getting Started with Latent Dirichlet Allocation using RTextTools + topicmodels

RTextTools bundles a host of functions for performing supervised learning on your data, but what about other methods like latent Dirichlet allocation? With some help from the topicmodels package, we can get started with LDA in just five steps. Text in

Read more »

Nomograms everywhere!

August 30, 2011
By
Nomograms everywhere!

At useR!, Jonty Rougier talked about nomograms, a once popular visualisation that has fallen by the wayside with the rise of computers. I’d seen a few before, but hadn’t understood how they worked or why you’d want to use them. Anyway, since that talk I’ve been digging around in biology books from the 60s and

Read more »

R combined gps-track plot of spatial intensity

August 30, 2011
By
R combined gps-track plot of spatial intensity

To get a quick impression about the temporal stay of places it is helpful to generate a plot of the trackpoints spatial density (intensity). As the 3d visualisation has both advatages and disadvantages, a combination with a 2D plot is useful to interpret the data. The data used in this example is a gps record

Read more »

Realized beta and beta equal 1

August 30, 2011
By
Realized beta and beta equal 1

What does beta look like in the out-of-sample period for the portfolios generated to have beta equal to 1? In the comments Ian Priest wonders if the results in “The effect of beta equal 1″ are due to a shift in beta from the estimation period to the out-of-sample period.  (The current post will make … Continue reading...

Read more »

How Much of R is Written in R Part 2: Contributed Packages

August 29, 2011
By
How Much of R is Written in R Part 2:  Contributed Packages

So that mean old boss of mine is at it again.  This morning I came in beaming about how many people had read my post How Much of R is Written in R (thanks by the way!).  He then asks me about one little line in that post; the one about how if you looked

Read more »

Sharing live R functions with OpenCPU

August 29, 2011
By
Sharing live R functions with OpenCPU

OpenCPU is a new initiative from R user Jeroen Ooms to make innovations in statistics, visualization and data-science more widely applicable. Based on open-source principles, it's a web-based service that lets you upload data visualizations and analyses as R scripts, and allow others to run them on demand. For example, you can upload a script to visualize a company's...

Read more »

another lottery coincidence

August 29, 2011
By
another lottery coincidence

Once again, meaningless figures are published about a man who won the French lottery (Le Loto) for the second time. The reported probability of the event is indeed one chance out of 363 (US) trillions (i.e., billions in the metric system. or 1012)… This number is simply the square of which is the number of

Read more »

The effect of beta equal 1

August 29, 2011
By
The effect of beta equal 1

Investment Performance Guy had a post about beta equal 1.  It made me wonder about the properties of portfolios with beta equal 1.  When I looked, I got a bigger answer than I expected. Data I have some S&P 500 data lying about from the post ‘On “Stock correlation has been rising”‘.  So laziness dictated … Continue reading...

Read more »

Comparing Two Distributions

August 29, 2011
By
Comparing Two Distributions

Here I compare two distributions, flowering duration of indigenous and allochtonous plant species. The hypothesis is that alien compared to indigenous plant species exhibit longer flowering periods.Read more »

Read more »