2450 search results for "gis"

How to: Binomial regression models in R

March 19, 2011
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How to: Binomial regression models in R

Ever wondered how to predict success or failure as a function of other variables? Here's a quick tutorial on binomial regression in R.

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Applying functions on groups: sqldf, plyr, doBy, aggregate or data.table ?

March 17, 2011
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Applying functions on groups: sqldf, plyr, doBy, aggregate or data.table ?

Which one of the sqldf, plyr, doBy and aggregate functions/packages would be faster for applying functions on groups of rows? I was wondering about this earlier in this post.  It seems sqldf would be the fastest according to a post in manipulatr m...

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Applying functions on groups: sqldf, plyr, doBy, aggregate or data.table ?

March 17, 2011
By
Applying functions on groups: sqldf, plyr, doBy, aggregate or data.table ?

Which one of the sqldf, plyr, doBy and aggregate functions/packages would be faster for applying functions on groups of rows? I was wondering about this earlier in this post.  It seems sqldf would be the fastest according to a post in manipulatr m...

Read more »

$3.2M in prizes for predicting hospitalization

March 17, 2011
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Heritage Health and Kaggle have teamed up to create the biggest data science competition thus far: the Heritage Health Prize, which challenges competitors to build a statistical model to predict the number of days a person is likely to spend in hospital over the next year, based on (anonymized) factors such as demographics, medical visits and treatments, and other...

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sab-R-metrics: Brief Sidetrack for Scatterplot Matrices

March 16, 2011
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sab-R-metrics: Brief Sidetrack for Scatterplot Matrices

In my last two posts I talked about Ordinary Least Squares, then extended this discussion to the multiple predictor case and briefly talked about some of the problems that may arise. These problems can include omitted variable bias, heteroskedasticity, non-normality, and multicollinearity. Most of these problems are relatively minor in practice and have easy fixes,...

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sab-R-metrics: Brief Sidetrack for Scatterplot Matrices

March 16, 2011
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sab-R-metrics: Brief Sidetrack for Scatterplot Matrices

In my last two posts I talked about Ordinary Least Squares, then extended this discussion to the multiple predictor case and briefly talked about some of the problems that may arise. These problems can include omitted variable bias, heteroskedasticity, non-normality, and multicollinearity. Most of these problems are relatively minor in practice and have easy fixes,...

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More pi plus 1 (or plus 0.01) day fun

March 15, 2011
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More pi plus 1 (or plus 0.01) day fun

Since I just didn’t get enough this morning, I spent some more time fooling around with estimating pi. Since I was basically counting the number of random x,y pairs inside a quarter circle and computing a sample average for more … Continue reading →

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Webinar on integrating R with applications, March 16

March 15, 2011
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A quick reminder that Revolution Analytics' CTO David Champagne will be hosting a live webinar tomorrow (March 16) on Integrating R into 3rd Party and Web Applications Using RevoDeployR. Designed for application developers, this webinar will cover publishing R scripts to the RevoDeployR server, and integrating their results into Web applications, Microsoft Excel, JasperReports Server and more. Complete details...

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I’m late for π day

March 15, 2011
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I’m late for π day

It is officially no longer pi day, but I didn’t see this Drew Conway post about estimating pi until just a few minutes ago. Because Google Reader doesn’t show github embeds, I also got to try it without seeing Drew’s … Continue reading →

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Happy Pi Day, Now Go Estimate It!

March 14, 2011
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Happy Pi Day, Now Go Estimate It!

As you may know, today is Pi Day, when all good nerds take a moment to thank the geeks of antiquity for their painstaking work in estimating this marvelous mathematical constant. It is also a great opportunity to thank contemporary geeks for the wonders of modern computing, which allow us to estimate pi to near

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