Monthly Archives: November 2011

Relation Between Fires and Distanse to the Nearest Road (Recalculated)

November 29, 2011
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Relation Between Fires and Distanse to the Nearest Road (Recalculated)

As you may already know, I'm a proud owner of AMD FX-8150 8-core CPU. And I've purchased it not for gaming reasons, but for science. My previous CPU was painfully slow with such calculations as determination of the relation between fires and distance t...

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Permanently Setting the CRAN repository

November 29, 2011
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Setting the CRAN repository so that it does not ask every time you try to install a package  is something that I think few people bother to do, but it is so simple and can save a fair bit of frustration when working.  This is accomplished through a setting in one of the Rprofile files.  There

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Review of "The Art of R Programming" by Norman Matloff

November 29, 2011
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By Joseph Rickert Anyone seeking to learn R faces two major challenges: (1) learning how to swim in the sea of information: R packages, books, websites, blog posts, message boards etc. that threatens to drown a newbie and (2) and coming to grips with the structure, syntax and features of the language itself. Having some idea of what one...

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Contributions to the R source

November 29, 2011
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One of the nice things about tracking the R subversion repository using git instead of subversion is you can do git shortlog -s -n which gives you 19855 ripley 6302 maechler 5299 hornik 2263 pd 1153 murdoch 813 iacus 716 luke 6...

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Example 9.16: Small multiples

November 29, 2011
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Example 9.16: Small multiples

Small multiples are one of the great ideas of graphics visionary Edward Tufte (e.g., in Envisioning Information). Briefly, the idea is that if many variations on a theme are presented, differences quickly become apparent. Today we offer general guida...

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Accessing and Visualising Sentencing Data for Local Courts

November 29, 2011
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Accessing and Visualising Sentencing Data for Local Courts

A recent provisional data release from the Ministry of Justice contains sentencing data from English(?) courts, at the offence level, for the period July 2010-June 2011: “Published for the first time every sentence handed down at each court in the country between July 2010 and June 2011, along with the age and ethnicity of each

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outersect(): The opposite of R’s intersect() function

November 29, 2011
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outersect(): The opposite of R’s intersect() function

The Objective To find the non-duplicated elements between two or more vectors (i.e. the ‘yellow sections of the diagram above) The Problem I needed the opposite of R’s intersect() function, an “outersect()“. The closest I found was setdiff() but the order of the input vectors produces different results, e.g. setdiff() produces all elements of the first

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A/B Testing in R – Part 1

November 29, 2011
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A/B testing is a method for comparing the effectiveness of several different variations of a web page. For example, an online clothing retailer that specializes in mens’ streetwear may want to examine whether a black or pink background results in more purchases from visitors to the site. Lets say that our online store is just

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Trading Strategy Sensitivity Analysis

November 28, 2011
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Trading Strategy Sensitivity Analysis

When designing a trading strategy, I want to make sure that small changes in the strategy parameters will not transform the profitable strategy into the loosing one. I will study the strategy robustness and profitability under different parameter scenarios using a sample strategy presented by David Varadi in the Improving Trend-Following Strategies With Counter-Trend Entries

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Dealing with R and HANA

November 28, 2011
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Dealing with R and HANA

First things first...what's "R"? Simply put...is a programming language and software environment for statistical computing and graphics. More infomation can be found here R on WikipediaI have code in many programming languages, some of them very commer...

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