2774 search results for "GIS"

Review of 2011 Data Scientist Summit

May 13, 2011
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Review of 2011 Data Scientist Summit

Some time over the past 6 weeks I randomly saw a tweet announcing the “Data Scientist Summit” and shortly below it I saw that it would be held in Las Vegas at the Venetian. Being a Data Scientist myself is reason enough to not pass up this opportunity, but Vegas definitely sweetens the deal! On Wednesday I woke up...

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Reflections on Data Science Summit 2011

May 13, 2011
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The Data Science Summit held in Las Vegas this week was outstanding - kudos and thanks to EMC/Greenplum for organizing the event. The energy of 150+ data scientists coupled with a well-curated agenda of talks created a real sense of being at the cusp of a real revolution in the applications of data analysis. Here are just a few...

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plyr’s idata.frame VS. data.frame

May 13, 2011
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plyr’s idata.frame VS. data.frame

I had seen the function idata.frame in plyr before, but not really tested it. Here are a few comparisons of operations on normal data frames and immutable data frames. Immutable data frames don't work with the doBy package, but do work with aggregate i...

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Kaggle Competition Walkthrough: Fitting a model

May 12, 2011
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Kaggle Competition Walkthrough: Fitting a model

Now that we've got the data we need into R, it is very easy to fit a model using the caret package. Caret's workhorse function is called 'train,' and it allows you to fit a wide variety of models using the same syntax. Furthermore, many models have '...

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sab-R-metrics: Basics of LOESS Regression

May 11, 2011
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sab-R-metrics: Basics of LOESS Regression

Last week, I left you off at logistic regression. This week, I'll be pushing the limits of regression analysis a bit more with a smoothing technique called LOESS regression. There are a number of smoothing methods that can be used, such as Smoothing ...

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sab-R-metrics: Basics of LOESS Regression

May 11, 2011
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sab-R-metrics: Basics of LOESS Regression

Last week, I left you off at logistic regression. This week, I'll be pushing the limits of regression analysis a bit more with a smoothing technique called LOESS regression. There are a number of smoothing methods that can be used, such as Smoothing ...

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Multivariate probit regression using (direct) maximum likelihood estimators

May 11, 2011
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Multivariate probit regression using (direct) maximum likelihood estimators

Consider a random pair of binary responses, i.e. with taking values 1 or 2. Assume that probability can be function of some covariates . The Gaussian vector latent structure A standard model is based a latent Gaussian structure, i.e. there exi...

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ABC model choice by DIC

May 10, 2011
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ABC model choice by DIC

Yet another paper on ABC model choice was posted on arXiv a few days ago, just prior to the ABC in London meeting that ended in the pub above (most conveniently located next to my B&B!). It is written by Olivier Francois and Guillaume Laval and the approach relies on DIC for running model selection.

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Data Science Toolset discussion at Data Scientist Summit

May 10, 2011
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Heads-up to anyone attending the sold-out Data Science Summit in Las Vegas this week: I'll be there tomorrow and Thursday for the conference and to discuss R on the panel discussion "Data Science Toolset - Recipes That Win" (more details about the panel discussion below.) I'm looking forward to meeting with the other R users there -- tweet or...

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Problems with plyr — the memory/complexity trade-off

May 10, 2011
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Two types of R users My overwhelming impression from UseR 2010 is that, generally speaking, there are 2 types of regular R users -- those who have heard and are made uncomfortable by the idea of the *apply() functions, and those who really get it. In ...

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