# Monthly Archives: January 2011

## Code: parsing Slovenian exchange rate data

January 30, 2011
By

﻿Some time ago I found myself in need of daily exchange rates for the Slovenian Tolar (though I can’t now remember why). Unfortunately, I wasn’t able to find the data in a readily usable format at the Bank of Slovenia … Continue reading →

## Data Mining with WEKA

January 30, 2011
By

There are a number of good open source projects for statistics and data mining, for example the software WEKA developed at the University of Waikato. The description on their website states that: Weka is a collection of machine learning algorithms for data mining tasks. The algorithms can either be applied directly to a dataset or

## Statistical Computing and Graphics Newsletter

January 30, 2011
By

The new issue (Vol. 21, No. 2) is out now. Featured articles are: barNest: Illustrating nested summary measures by Jim Lemon and Ofir Levy You say “graph invariant,” I say “test statistic” by Carey E. Priebe, Glen A. Coppersmith and Andrey Rukhin Computation in Large-Scale Scientific and Internet Data Applications is a Focus of MMDS 2010

## Tab completion

January 30, 2011
By

Let's say your hands are aching from too much typing in of variables. What to do? Get a keyboard tray and learn proper ergonomics, of course.But what if you just want to reduce the amount of typing in of variables you do for reasons of laziness...err...

## R exam

January 30, 2011
By
$R exam$

I spent most of my Saturday perusing R codes to check the answers written by my students to the R exam I gave two weeks ago… The outcome is mostly poor, even though some managed to solve a fair part of the long problem. Except for the few hopeless cases who visibly never wrote a

## Boxplots and Beyond – Part I

Boxplots are a simple and reasonably popular way of summarizing the range of variation of a real-valued variable across different subsets of data.  Typical examples might include diastolic blood pressure across a group of patients, broken dow...

## R programming books (updated)

January 28, 2011
By

In a recent post, I asked for suggestions for introductory R computing books. In particular, I was looking for books that: Assume no prior knowledge of programming. Assume very little knowledge of statistics. For example, no regression. Are cheap, since they are for undergraduate students. Some of my cons aren’t really downsides as such. Rather,

## Converting strsplit() output to a data.frame

January 28, 2011
By

R has a nice set of utilities to work with strings. Function paste is surely one among these. It can be used to "glue" several strings with optional separator. The following example shows how paste can be used to create a new variable in a dataset: dat (dat\$z Today I was in a situation where I only had column...

## Homicides in Mexico 2006-2009

January 27, 2011
By

Just today the Mexican government released to the public the mortality database for 2009, and as you can see from the chart Mexico has suffered from a steep rise in homicides from 2008 onward and very likely reached the highest violence rate in recent history last year. Since the Mexican government also recently made...

## ABC model choice not to be trusted [2]

January 27, 2011
By

As we were completing our arXiv summary about ABC model choice, we were helpfully pointed to a recent CRiSM tech. report by X. Didelot, R. Everitt, A. Johansen and D. Lawson on  Likelihood-free estimation of model evidence. This paper is quite related to our study of the performances of the ABC approximation to the Bayes