# Monthly Archives: December 2010

## A new blog about using R for ecology and evolution

December 27, 2010
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I am starting this blog not because I am a seasoned code writer, but because I am learning how to use R specifically for ecology and evolution, and figured many others might have the same questions I have. If I find cool solutions I will post them here...

## The tightrope of the random walk

December 27, 2010
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We’re really interested in markets, but we’ll start with a series of coin tosses.  If the coin lands heads, then we go up one; if it lands tails, we go down one. Figure 1: A coin toss path.Figure 1 is the result of one thousand coin flips.  It is a random walk. The R command … Continue reading...

## R/Finance 2011 Call for Papers

December 26, 2010
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The 2011 R/Finance conference has an updated call for papers.  Dirk Eddelbuettel announced it to the R-SIG-Finance mailing list.  I've reproduced his email in its entirety below.  Let me know if you plan on attending.Subject: R/Finance 2...

## R/Finance 2011 Call for Papers

December 26, 2010
By

The 2011 R/Finance conference has an updated call for papers.  Dirk Eddelbuettel announced it to the R-SIG-Finance mailing list.  I've reproduced his email in its entirety below.  Let me know if you plan on attending.Subject: R/Finance 2...

## Graphics *and* Statistics: The Facebook Map

December 26, 2010
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There is this beautiful graph created by the facebook intern Paul Butler showing all (?) connections between facebook accounts: Paul’s article is called “Visualizing Friendships“, which I would more call “Visualizing connections between facebook accounts”, but that is probably a different matter. Although this is a beautiful piece of artwork, from a statistical point of

## 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