Monthly Archives: November 2011

Cycles in finite populations: A reproducible seminar in three acts

November 1, 2011
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Cycles in finite populations: A reproducible seminar in three acts

For this years Halloween I presented the mathematical biology seminar at the Centre for Mathematical Biology. Here is the title and the abstract… Cycles in finite populations: a reproducible seminar in three acts Many natural populations exhibit cyclic fluctuations. Explaining the underlying … Continue reading →

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Generating PPC Keywords in R

November 1, 2011
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Paid search marketing refers to the process of driving traffic to a website by purchasing ads on search engines. Advertisers bid on certain keywords that users might search for, and that determines when and where their ads appear. For example, an individual who owns an auto dealership would want to bid on keywords relating to automobiles

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Selecting statistics for ABC model choice [R code]

November 1, 2011
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Selecting statistics for ABC model choice [R code]

As supplementary material to the ABC paper we just arXived, here is the R code I used to produce the Bayes factor comparisons between summary statistics in the normal versus Laplace example. (Warning: running the R code takes a while!) Filed under: R, Statistics, University life Tagged: ABC, Bayesian model choice, Laplace distribution, R, summary

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How much does "Beta" change depending on time?

November 1, 2011
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How much does "Beta" change depending on time?

You may often use "Beta" to measure the market exposure of your portfolio because it's easy to calculate.Since I have been wondering how much "Beta" change depending on time, more precisely writing, data-set and the period of return time series, I...

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R 2.14 for Windows: now with SVG support

November 1, 2011
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One additional new feature in the latest release of R: the standard binaries of R 2.14 from the R Project now include Cairo support. For Windows users, this means that you can now create SVG graphics in R -- the best format for displaying R graphics on the web -- without having to compile R yourself. Note that if...

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Evolving Domestic Frontier

November 1, 2011
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Evolving Domestic Frontier

When we learn the efficient frontier, most are misled to believe that the frontier is static and unchanging.  However, we should have all learned by recent experience that the frontier is as volatile as the assets that construct it.  If we lo...

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Use case: combining taxize and rgbif

November 1, 2011
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Use case: combining taxize and rgbif

Sure thing….this is just the sort of thing for which rOpenSci is being built. A colleague of mine recently saw our packages in development and thought, “Hey, that could totally make my life easier.”   What was made easier you ask?   This was his situation: He had a list of ca. 1200 species of

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Computing on the Language Followup

November 1, 2011
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My article on computing on the language was unexpectedly popular and so I wanted to quickly follow up on my own solution. Many of you got the answer, and in fact many got solutions that were quite a bit shorter than mine. Here’s how I did it: makeList

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Teaching with R: the tools

November 1, 2011
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I bought an Android phone, nothing fancy just my first foray in the smartphone world, which is a big change coming from the dumb phone world(*). Everything is different and I am back at being a newbie; this is what … Continue reading →

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Code Optimization: One R Problem, Ten Solutions – Now Eleven!

November 1, 2011
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Code Optimization: One R Problem, Ten Solutions – Now Eleven!

Earlier this year I came across a rather interesting page about optimisation in R from rwiki. The goal was to find the most efficient code to produce strings which follow the pattern below given a single integer input n: From this we can see that the general pattern for n is: It is rather heart

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