March 2010

How ideological is Google?

March 31, 2010 | David Smith

Adam Bonica, a grad student in political science at NYU, recently published a ranking of the political slant of various professions, based on the amount and recipient (Republican or Democratic) of political donations by lawyers, lobbyists, physicians and many other occupations. This paper (PDF) gives the complete analysis, but the ... [Read more...]

Predicting April month return

March 31, 2010 | kafka

Bespoke blogged about average monthly returns of the DJI and emphasized April. Before jumping on that information, let’s check some weak points. In that post, only average returns are presented. We need at least extreme points (min;max) and confidence ranges. Second problem – the normal market have upward trend ...
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Lotka-Volterra model ~ intro

March 30, 2010 | apeescape

So many know about the Lotka-Volterra model (i.e. the predator-prey model) in ecology. This model portrays two species, the predator (y) and the prey (x), interacting each other in limited space. The prey grows at a linear rate () and gets eaten by the predator at the rate of (). The ... [Read more...]

Some Code for Dumping Data from Twitter Gardenhose

March 30, 2010 | Ryan

Gardenhose is a Streaming API feed that continuously sends a sample (roughly 15% according to Ryan Sarver at the 140tc in September 2009) of all tweets to feed recipients. This is some code for dumping the tweets to files named by date and hour. It is in PHP which is not my ... [Read more...]

TTR_0.20-2 on CRAN

March 30, 2010 | Joshua Ulrich

An updated version of TTR is now on CRAN. It fixes a couple bugs and includes a couple handy tweaks. Here's the full contents of the CHANGES file:TTR version 0.20-2 Changes from version 0.20-1NEW FEATURES:Added VWAP and VWMA (thanks to Brian Peterson...
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Scientists misusing Statistics

March 30, 2010 | David Smith

In ScienceNews this month, there's controversial article exposing the fact that results claimed to be "statistically significant" in scientific articles aren't always what they're cracked up to be. The article -- titled "Odds Are, It's Wrong" is interesting, but I take a bit of an issue with the sub-headline, "Science ... [Read more...]

Smoothing time series with R

March 29, 2010 | David Smith

Smoothing is a statistical technique that helps you to spot trends in noisy data, and especially to compare trends between two or more fluctuating time series. It's a useful visualization tool that I'm pleased to see cropping up more and more in statistical graphics on the Web -- it's now ... [Read more...]

Looking for Software Paths in Windows Registry

March 28, 2010 | Yihui Xie

hen we want to call external programs in R under Windows, we often need to know the paths of these programs. For instance, we may want to know where ImageMagick is installed, as we need the convert (convert.exe) utility to convert images to other formats, or where OpenBUGS is ... [Read more...]

Finance::YahooQuote 0.24

March 26, 2010 | Thinking inside the box

Having espoused rule number one in regression testing in the post about yesterday's bug fix upload 0.23, we can now add rule number zero: Do not introduce a new error by omitting the trailing semicolon. I guess it shows that I don't really program in... [Read more...]

Rcpp 0.7.11

March 26, 2010 | Thinking inside the box

A new versions 0.7.11 of Rcpp is awaiting inclusion into CRAN and Debian. It is also available from here. This version fixes a somewhat serious bug uncovered by Doug Bates when working with vectors of strings. We also added a few new accessor func... [Read more...]

Code Highlights in WordPress

March 26, 2010 | Lee

I’ve come across a very useful plugin for WordPress which highlights code in posts using GeSHi called WP-Syntax. This plugin is easy to use and adds highlights simply by putting the appropriate tags around code blocks. For instance, we can make the following R code much more readable by ... [Read more...]

Predicting Pizza

March 26, 2010 | David Smith

What's the secret to the best pizza in New York? That's what statistical consultant and R user Jared Lander sought to find out, by analyzing the rankings of NY pizza joints at, and building a regression model for ratings based on variables like localion, price, number of reviews, ... [Read more...]

Summarising data using dot plots

March 26, 2010 | Ralph

A dot plot is a type of display that compares counts, frequencies, totals or other summary measures for a series of categories. The dot plot can be arranged with the categories either on the vertical or horizontal axis of the display to allow comparising between the different categories as well ...
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BioMart (and biomaRt)

March 26, 2010 | nsaunders

I’ve been vaguely aware of BioMart for a few years. Inexplicably, I’ve only recently started to use it. It’s one of the most useful applications I’ve ever used. The concept is simple. You have a set of identifiers that describe a biological object, such as a ... [Read more...]
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