Posts Tagged ‘ computing ’

Time Series Data Library now on DataMarket

June 19, 2012
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The Time Series Data Library is a collection of about 800 time series that I have maintained since about 1992, and hosted on my personal website. It includes data from a lot of time series textbooks, as well as many other series that I’ve either collected for student projects or helpful people have sent to me. I’ve now moved...

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Visualization of Reading Level Frequency by Congressional Bill Stage

April 15, 2012
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Visualization of Reading Level Frequency by Congressional Bill Stage

  Here’s a fun example of how you might use my data on Congressional bill length and complexity.  Imagine you want to understand the empirical distribution of Flesch-Kincaid reading level for Congressional bills and how this distribution is related to … Continue reading →

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The art of R programming

November 29, 2011
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The art of R programming

This is a gem of a book. It will become the book I give PhD students when they are learning how to write good R code. That is, if I ever see it again. I had hoped to write a review of it, but I haven’t seen it since it arrived in the mail a

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What you wish you knew before you started a PhD

November 11, 2011
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What you wish you knew before you started a PhD

I asked my research group recently what they wished they had learned before they started work on a PhD. Here are some of the responses. More mathematics. Particular topics they named included real analysis, functional analysis, measure theory, algebra, linear algebra. That would have been my response also. I still wish I knew more mathematics than

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The Joy of R: A Feline Guide

November 5, 2011
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The Joy of R: A Feline Guide

Just because it’s caturday Images by Mario Pineda-Krch (CC BY-NC-SA 3.0) This is from the “Mario’s Entangled Bank” blog ( http://pineda-krch.com ) of Mario Pineda-Krch, a theoretical biologist at the University of Alberta. Filed under: cats, computing, humour, R, Sweave

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Vanilla C code for the Stochastic Simulation Algorithm

October 24, 2011
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Vanilla C code for the Stochastic Simulation Algorithm

The Gillespie stochastic simulation algorithm (SSA) is the gold standard for simulating state-based stochastic models. If you are a R buff, a SSA novice and want to get quickly up and running stochastic models (in particular ecological models) that are not … Continue reading →

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Character occurrence in passwords

June 16, 2011
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Character occurrence in passwords

As everyone knows, it seems that Sony is taking a bit of a battering from hackers.  Thanks to Sony, numerous account and password details are now circulating on the internet. Recently, Troy Hunt carried out a brief analysis of the password structure. Here is a summary of his post: There were around 40,000 passwords, of which

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Comparing HoltWinters() and ets()

May 29, 2011
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I received this email today: I have a question about the ets() function in R, which I am trying to use for Holt-Winters exponential smoothing. My problem is that I am getting very different estimates of the alpha, beta and gamma parameters using ets() compared to HoltWinters(), and I can’t figure out why. This is

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Makefiles and Sweave

May 12, 2011
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Makefiles and Sweave

A Makefile is a simple text file that controls compilation of a target file. The key benefit of using Makefile is that it uses file time stamps to determine if a particular action is needed. In this post we discuss how to use a simple Makefile that compiles a tex file that contains a number

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R 2.12 to 2.13 package upgrade

April 14, 2011
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R 2.12 to 2.13 package upgrade

If you: use Linux have just upgraded your R installation from 2.12 to 2.13 installed some/all of your packages in your home area (e.g. ~/R/i486-pc-linux-gnu-library/2.12) and… …are wondering why R can’t see them any more just do this: # at a shell prompt cp ~/R/i486-pc-linux-gnu-library/2.12 ~/R/i486-pc-linux-gnu-library/2.13 # in R console update.packages(checkBuilt=TRUE, ask=FALSE) # back to

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