2738 search results for "gis"

Update to Graphing Non-Proportional Hazards in R

December 30, 2012
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Update to Graphing Non-Proportional Hazards in R

Update 1 February 2013: I've moved all of the functionality described in this post into an R package called simtvc. Have a look. It is much easier to use. This is a quick update for a previous post on Graphing Non-Proportional Hazards in R. In the previous post I showed how to simulate and graph 1,000...

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Row-wise summary curves in faceted ggplot2 figures

December 29, 2012
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Row-wise summary curves in faceted ggplot2 figures

I really enjoy reading the Junk Charts blog.  A recent post made me wonder how easy it would be to add summary curves for small-multiple type plots, assuming the “small multiples” to summarize were the X component of a ggplot2::facet_grid(Y ~ X) … Continue reading →

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Men who stare at needles

December 29, 2012
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Buffon's needle problem is a question first posed in the 18th century by Georges-Louis Leclerc, Comte de Buffon:What is the probability that a needle thrown at a lined sheet of paper will cross a line?This problem can be used to estimate π. If we set the nail size and the line distance = 1, the estimator can be calculated...

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My Intro to Multiple Classification with Random Forests, Conditional Inference Trees, and Linear Discriminant Analysis

December 27, 2012
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My Intro to Multiple Classification with Random Forests, Conditional Inference Trees, and Linear Discriminant Analysis

After the work I did for my last post, I wanted to practice doing multiple classification.  I first thought of using the famous iris dataset, but felt that was a little boring.  Ideally, I wanted to look for a practice … Continue reading →

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Who Survived on the Titanic? Predictive Classification with Parametric and Non-parametric Models

December 24, 2012
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Who Survived on the Titanic? Predictive Classification with Parametric and Non-parametric Models

I recently read a really interesting blog post about trying to predict who survived on the Titanic with standard GLM models and two forms of non-parametric classification tree (CART) methodology. The post was featured on R-bloggers, and I think it's worth a closer look. The basic idea was to figure out which of these three

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Make a Christmas Tree in R with random ornaments/presents

December 24, 2012
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Make a Christmas Tree in R with random ornaments/presents

Happy holidays!     Link to Gist

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24 Christmas Gifts from is.R

December 24, 2012
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24 Christmas Gifts from is.R

The is.R blog has been on a roll in December with their Advent CalendaR feature: daily tips about R to unwrap each day leading up to Christmas. If you haven't been following it, start with today's post and scroll down. Sadly there isn't a tag to collect all these great posts together, but here are a few highlights: December...

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Latent Class Analysis with poLCA

December 24, 2012
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Latent Class Analysis with poLCA

On an airplane the other day, I learned of a method called latent class (transition) analysis, and it sounded like an interesting thing to try in R. Of course, as with everything R, There is a Package for That, called poLCA, written by none other than Drew Linzer (of Votamatic fame) and Jeffrey Lewis. I...

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Measuring the Gerrymander with spatstat

December 23, 2012
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Measuring the Gerrymander with spatstat

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...

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The definitive guide to plotting confidence intervals in R

December 22, 2012
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The definitive guide to plotting confidence intervals in R

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...

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