3174 search results for "GIS"

Using a GBM for Classification in R

August 26, 2013
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I discuss some advantages of Generalized Boosted Models over logistic regression and discriminant analysis and demonstrate how to use a GBM for binary classification (predicting whether an event occurs or not). Using a GBM for Classification in R from...

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predictNLS (Part 2, Taylor approximation): confidence intervals for ‘nls’ models

August 26, 2013
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predictNLS (Part 2, Taylor approximation): confidence intervals for ‘nls’ models

Initial Remark: Reload this page if formulas don’t display well! As promised, here is the second part on how to obtain confidence intervals for fitted values obtained from nonlinear regression via nls or nlsLM (package ‘minpack.lm’). I covered a Monte Carlo approach in http://rmazing.wordpress.com/2013/08/14/predictnls-part-1-monte-carlo-simulation-confidence-intervals-for-nls-models/, but here we will take a different approach: First- and second-order

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GDAT Class October 14-18, 2013

August 25, 2013
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GDAT Class October 14-18, 2013

This is your fast track to enterprise performance analysis and capacity planning with an emphasis on applying R statistical tools to your performance data. Early-bird discounts are available for the Level III Guerrilla Data Analysis Techniques class O...

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The Wonders of foreach

August 25, 2013
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The Wonders of foreach

Writing code from scratch to do parallel computations can be rather tricky. However, the packages providing parallel facilities in R make it remarkably easy. One such package is foreach. I am going to document my trail of discovery with foreach, which began some time ago, but has really come into fruition over the last few

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Using R in Used Car Search

August 24, 2013
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Using R in Used Car Search

Recently I was looking to buy a used car. I was using the Edmunds website to estimate the true market value of a used car. It has a nice click through interface where it guides you to input make, model, … Continue reading →

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New Webinar: High Performance Predictive Analytics in R and Hadoop

August 23, 2013
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This coming Tuesday, August 27, our US Chief Scientist Mario Inchosa will reveal some details of the forthcoming in-Hadoop predictive analytics capabilities of Revolution R Enterprise 7, due for release later this year. Here's the abtract of his webinar, High Performance Predictive Analytics in R and Hadoop: Hadoop is rapidly being adopted as a major platform for storing and...

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Exploring the robustness of Bayes Factors: A convenient plotting function

August 23, 2013
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Exploring the robustness of Bayes Factors: A convenient plotting function

One critique frequently heard about Bayesian statistics is the subjectivity of the assumed prior distribution. If one is cherry-picking a prior, of course the posterior can be tweaked, especially when only few data points are at hand. For example, see the Scholarpedia article on Bayesian statistics: In the uncommon situation that the data are extensive

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GitHub renders CSV in the browser, becomes even better for social data set creation

August 22, 2013
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GitHub renders CSV in the browser, becomes even better for social data set creation

I've written in a number of places about how GitHub can be a great place to store data. Unlike basically all other web data storage sites (many of which I really like such as Dataverse and FigShare) GitHub enables deep social data set development and f...

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Quantifying uncertainty around R-squared for generalized linear mixed models

August 22, 2013
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Quantifying uncertainty around R-squared for generalized linear mixed models

People love $R^2$. As such, when Nakagawa and Schielzeth published an article in the journal Methods in Ecology and Evolution earlier this year, ecologists (amid increasing use of generalized linear mixed models (GLMMs)) rejoiced. Now there’s an R function that automates $R^2$ calculations for GLMMs fit with the lme4 package. $R^2$ is usually reported as a...

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Date Formats in R

August 22, 2013
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Importing DatesDates can be imported from character, numeric, POSIXlt, and POSIXct formats using the as.Date function from the base package.If your data were exported from Excel, they will possibly be in numeric format. Otherwise, they will m...

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