# 3905 search results for "git"

## Binary Classification – A Comparison of “Titanic” Proportions Between Logistic Regression, Random Forests, and Conditional Trees

December 23, 2012
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Now that I’m on my winter break, I’ve been taking a little bit of time to read up on some modelling techniques that I’ve never used before. Two such techniques are Random Forests and Conditional Trees.  Since both can be used … Continue reading →

## Measuring the Gerrymander with spatstat

December 23, 2012
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Well, to be specific, I mean measuring district compactness (a very interesting subject, see these three articles for starters). There are myriad ways of measuring the “oddness” of a shape, including a comparison of the area of the district to its circumcircle, the moment of inertia of the shape, the probability that a path connecting...

## Visualizing Principal Components

December 22, 2012
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Principal Component Analysis (PCA) is a procedure that converts observations into linearly uncorrelated variables called principal components (Wikipedia). The PCA is a useful descriptive tool to examine your data. Today I will show how to find and visualize Principal Components. Let’s look at the components of the Dow Jones Industrial Average index over 2012. First,

## The definitive guide to plotting confidence intervals in R

December 22, 2012
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Here at is.R(), we have produced countless posts that feature plots with confidence intervals, but apparently none of those are easy to find with Google. So, today, for the purposes of SEO, we’ve put “plotting confidence intervals” in the title of our post. We also cannot resist an earnest plea from our...

## Simple data simulator for the 2PL model

December 21, 2012
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The function: This is a very simple data simulator for a 2PL Model. This is just to get you started, from here is easy to add function parameters for indicating item locations and slopes or person distribution characteristics. The function accepts on...

## Computing an empirical pFDR in R

December 21, 2012
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The positive false discovery rate (pFDR) has become a classical procedure to test for false positive. It is one of my favourite because it rely on a re-sampling approach.I base my implementation on John Storey PNAS paper and the technical report he published with Rob Tibshirani while at Stanford (I find the technical report...

## Beautiful network diagrams with ggplot2

December 21, 2012
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I don’t usually like describing my own work as “beautiful,” but with your permission I will make an exception today. There have been some requests for scripts illustrating the plotting of network diagrams with ggplot2, and today (for the winter solstice) we’re bringing you a really nice-looking way of doing just that. In fact, this Gist...

## Y2K38: Our Own Mayan Calendar…Again

December 21, 2012
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$Y2K38: Our Own Mayan Calendar…Again$

It’s not quite the end of the world as we know it.  We made it through December 21, 2012 unscathed. It’s not going to be the last time we will make it through such a pseudo-calamity.  After all we have built our own end of the world before (e.g. Y2K). Next up January 19, 2038.

## Simple data simulator for the Rasch Model

December 21, 2012
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The function: This is a very simple data simulator for the Rasch Model.This is just to get you started, from here is easy to add function parameters for indicating item locations or person distribution characteristics. The function accepts only two p...