# Monthly Archives: December 2010

## Age and happiness: The pattern isn’t as clear as you might think

December 26, 2010
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A couple people pointed me to this recent news article which discusses "why, beyond middle age, people get happier as they get older." Here's the story: When people start out on adult life, they are, on average, pretty cheerful. Things... ...

## Autocorrelation Matrix in R

December 25, 2010
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I have been simulating a lot of data lately  with various covariance (correlation) structures, and one that I have been using is the autocorrelation (or autoregressive) structure, where there is a “lag” between variables. The matrix is a v-dimension matrix of the form \begin{bmatrix} 1 & \rho & \rho^2 & \dots & \rho^{v-1}\\ \rho &

## Has the seed that gets software development out of the stone-age been sown?

December 25, 2010
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A big puzzle for archaeologists is why stone age culture lasted as long as it did (from approximately 2.5 millions years ago until the start of the copper age around 6.3 thousand years ago). Given the range of innovation rates seen in various cultures through-out human history a much shorter stone age is to be

## Rcpp 0.9.0 announcement

December 25, 2010
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The text below went out as a post to the r-packages list a few days ago, but I thought it would make sense to post it on the blog too. So with a little html markup... Summary Version 0.9.0 of the Rcpp package is now on CRAN and its mirrors. Thi...

## one-dimensional integrals

December 25, 2010
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$one-dimensional integrals$

The foundamental idea of numerical integration is to estimate the area of the region in the xy-plane bounded by the graph of function f(x). The integral was esimated by divide x to small intervals, then add all the small approximations to give a total approximation. Read More: 468 Words Totally

## Chromosome bias in R, my notebook

December 23, 2010
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My goal is to develop a means of detecting chromosome bias from a human BAM file.Because I've been working with proprietary and novel plant genomes for the last three years, I haven't had the chance to use any of the awesome UCSC-based annotational features that have been introduced and refined in Bioconductor until now. I've returned to biomedical research...

## Did you feel that?

December 23, 2010
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There was a small earthquake in northern England on Tuesday. Barry Rowlingson felt the quake (it rattled the photographs on his wall), but didn't know how big of a quake it was because he didn't know how close he was to the epicentre. The British Geological Survey hadn't yet announced the quake, but did give access to seismograph readings,...

## Citizen Data Journalism: Mexico Homicides

December 23, 2010
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I've recently praised some mainstream media outlets like the New York Times and New Scientist for leading the charge on data journalism. But you don't need to be a large organization to find news in data. With open data sources, and open-source data analysis tools, individuals can make newsworthy discoveries. Diego Valle-Jones has been investigating the impact of the...

## R function to convert degrees to radians

December 23, 2010
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I would have never imagined that I would have to go back to high school concepts and do strange trigonometric calculations. However, it happened to me that I needed to convert GPS coordinates of a large data set to radians. It’s a trivial task, if you know how to do it. The function takes as

## Project Euler — Problem 187

December 23, 2010
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http://projecteuler.net/index.php?section=problems&id=187 A composite is a number containing at least two prime factors. For example, 15 = 3 × 5; 9 = 3 × 3; 12 = 2 × 2 × 3. There are ten composites below thirty containing precisely two, not necessarily distinct, prime factors: 4, 6, 9, 10, 14, 15, 21, 22, 25, 26. Read...