# Monthly Archives: May 2011

## Music file graphs with R

May 22, 2011
By

Today we will use R to extract some interesting summary statistics regarding the music files stored in the computer. For all mp3 files I keep certain metadata in their ID3 tag. We will use this information to explore the distribution of music files with respect to the year of release. All the following are done

## Comparing Student outcomes with Research Output (using R and ggplot2′s text labels)

May 22, 2011
By

In this post, I take a look at some league table data recently published by the Guardian. I also provide …Continue reading »

## Terry’s spiel

May 22, 2011
By

“We don’t need likelihood functions; we just need to know how to simulate from (…) We don’t need models with sufficient statistics; we just need summary statistics (…) We don’t need to be Bayesian; we just need to be approximately so. We don’t need theory to tell us our method works; we just need

## Slowing down matrix multiplication in R

May 21, 2011
By

After I realized that some aspects of R’s implementation are rather inefficient, one of the first things I looked at was matrix multiplication.  There I found a huge performance penalty for many matrix multiplies, a penalty which remains in the current version, 2.13.0.  As discussed below, eliminating this penalty speeds up long vector dot products

## The distribution of interestingness

On April 22, David Landy posed a question about the distribution of interestingness values in response to my April 3rd post on “Interestingness Measures.”  He noted that the survey paper by Hilderman and Hamilton that I cited there makes the following comment: “Our belief is that a useful measure of interestingness should generate index values that are reasonably distributed throughout...

## [Project Euler] – Problem 58

May 21, 2011
By

Starting with 1 and spiralling anticlockwise in the following way, a square spiral with side length 7 is formed. 37 36 35 34 33 32 31 38 17 16 15 14 13 30 Read More: 597 Words Totally

## Defaults, Lists and Classes: A Functional Post

May 20, 2011
By

In this post, I demonstrate a couple of useful tricks to writing functions in R. The context is a function I wrote called called samp() that allows for an easy demonstration of sampling distribution properties.DefaultsBy default, this function draws K...

## My programming journey

May 20, 2011
By

When clearing out some of my old programming books the other day I realised how far I’d come with programming over the years, and the number of different technologies that I have used over time. I thought I’d do a little summary post going from first programming experience to now – and it’s amazing what’s

## Long XLU Short SPY Part 2 (More History)

May 20, 2011
By

THIS IS NOT INVESTMENT ADVICE.  YOU ARE RESPONSIBLE FOR YOUR OWN GAINS AND LOSSES. The Fed is on a roll adding BAC ML Bond Indicies and now complete history for the four primary Dow Jones Indexes, so I wanted to extend my first post Long XLU Shor...

## Hacking the Kinect with R

May 20, 2011
By

I was browsing through the draft abstract booklet for this year's worldwide R user conference useR! 2011, and noticed this abstract: KinectR – Kinect interface to R Landon Jensen Microsoft launched the Kinect for Xbox 360 in late 2010 and it quickly broke records as the fastest selling consumer electronics device in history (8 million units sold in the...