Monthly Archives: August 2009

RSRuby in the IRB console

August 6, 2009
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RSRuby in the IRB console

R is terrific, of course, for all your statistical needs. But those data structures! “Everything is a list.” Leading to such wondrous ways to access variables as “p <- Meta(gds)$platform", or "last <- mylist]])]". Sometimes, you want something more familiar. An array, a hash, a hash of arrays. Or, you may

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Simple linear regression

August 5, 2009
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We use the regression analysis when, from the data sample, we want to derive a statistical model that predicts the values of a variable (Y, dependent) from the values of another variable (X, independent). The linear regression, which is the simplest and most frequent relationship between two quantitative variables, can be positive (when X increase, Y increase too) or...

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Simple linear regression

August 5, 2009
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We use the regression analysis when, from the data sample, we want to derive a statistical model that predicts the values of a variable (Y, dependent) from the values of another variable (X, independent). The linear regression, which is the simplest and most frequent relationship between two quantitative variables, can be positive (when X increase, Y increase too) or...

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R 64 bit on Mac OSX with ESS

August 5, 2009
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Table of contents Compiling Getting ESS to workThe current R version comes also with a 64-bit version so its not necessary to compile it from source anymore, but you do need to tell ESS how to use the 64bit version So today I compiled 64 bit R 2.91 on Mac OS X 10.5.7 in order to get maximum...

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R 64 bit on Mac OSX with ESS

August 5, 2009
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Table of contentsCompiling Getting ESS to workThe current R version comes also with a 64-bit version so its not necessary to compile it from source anymore, but you do need to tell ESS how to use the 64bit version So today I compiled 64 bit R 2.91 on Mac OS X 10.5.7 in order to get maximum...

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Code Snippet : List of CRAN packages

August 5, 2009
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This is a really simple code snippet that shows how to get the list of CRAN packages and their titles from the html page html page (toulouse mirror in this example)....Note that R has the available.packages function, but it does not give th...

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Locate the position of CRAN mirror sites on a map using Google Maps

August 5, 2009
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Locate the position of CRAN mirror sites on a map using Google Maps

Inspired by this post (suggested here by the always useful Revolutions blog), I attempted to plot the position of CRAN mirrors on a map taking advantage of the nice R package RgoogleMaps (check the dependencies!). Below the code:library(XML) # downlo...

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My Procedure for Upgrading R: Windows XP with StatET

August 5, 2009
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My Procedure for Upgrading R: Windows XP with StatET

R releases upgrades around every 6 months. I run R on Windows XP using the StatET plug-in and Eclipse. This is my current upgrade procedure. I've posted this mainly for my own future reference. But who knows? it might be useful for someone else:1. Down...

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Contingency table and the study of the correlation between qualitative variables: Pearson’s Chi-squared test

August 4, 2009
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If you have qualitative variable, it is possible to verify the correlation by studying a contingency table R by C, using the Pearson's Chi-squared test.A casino wants to study the correlation between the modes of play and the number of winners by age group, to see if the number of winners depends on the type of game that you...

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Contingency table and the study of the correlation between qualitative variables: Pearson’s Chi-squared test

August 4, 2009
By

If you have qualitative variable, it is possible to verify the correlation by studying a contingency table R by C, using the Pearson's Chi-squared test.A casino wants to study the correlation between the modes of play and the number of winners by age group, to see if the number of winners depends on the type of game that you...

Read more »