1539 search results for "regression"

Terrain effects on SUHI estimates

November 9, 2012
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Terrain effects on SUHI estimates

Introduction Zhang and Imhoff (2010)  pdf here utilized NLCD impervious surface area (ISA), Olson biomes, and MODIS Land Surface temperature (LST) to estimate the magnitude of UHI in large cities across the US.  Peng  employed a   similar approach in studying 419 large cities ( population greater than 1m ) around world. Peng’s work suggests a limit or

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Data types part 2: Using classes to your advantage

November 8, 2012
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Data types part 2: Using classes to your advantage

Last week I talked about objects including scalars, vectors, matrices, dataframes, and lists.  This post will show you how to use the objects (and their corresponding classes) you create in R to your advantage.First off, it's important to remember...

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What’s new in Revolution R Enterprise 6.1

November 8, 2012
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We're pleased to announce that the latest update to Revolution R Enterprise is available today! Existing subscribers will soon receive an email with update instructions, and the free academic distribution will be updated later today. Version 6.1 adds a frequently-requested big-data statistical modeling algorithm, adds new connectivity option for Hadoop, improves performance, and provides new security and installation options...

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In case you missed it: October 2012 Roundup

November 7, 2012
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In case you missed them, here are some articles from October of particular interest to R users. Sponsorships for local R user groups from Revolution Analytics are now open to applicants worldwide. During the landfall of Hurricane Sandy in the US, several R-based apps used public weather and social media data to document its impact, like this timeline of...

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Webinar Thursday: How R is used to optimize tractor production at John Deere

November 6, 2012
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I just sat in on the rehearsal for Thursday's webinar by John Deere's Derek Hoffman, Order Fulfillment Forecasting at John Deere: How R Facilitates Creativity and Flexibility. Derek will give a spirited argument of why R is critical for the faming equipment manufacturer's operations: from forecasting demand for equipment, forecasting crop yields (they produce forecasts for more than half...

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Multi-stage sampling together with hierarchical/ mixed effects models: which packages?

November 5, 2012
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Dear R experts, I sent this question to the r-help list but didn’t get much response, probably because it is more of a stats question. But as this blog is syndicated on r-bloggers I thought I would try it again here on this blog. If I am barking up the wrong tree, feel free to

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Unstable parallel simulation, or after finishing testing, test some more

November 2, 2012
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Lately I have been working on a trading system based on Support Vector Machine (SVM) regression (and yes, if you wonder, there are a few posts planned to share the results). In this post however I want to share an interesting problem I had to deal with. Few days ago, I started running simulations using

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Why pictures are so important when modeling data?

October 31, 2012
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Why pictures are so important when modeling data?

(bis repetita) Consider the following regression summary,Call: lm(formula = y1 ~ x1)   Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 3.0001 1.1247 2.667 0.02573 * x1 0.5001 0.1179 4.241 0.00217 **...

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Hierarchical linear models and lmer

October 31, 2012
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Hierarchical linear models and lmer

Hierarchical linear models and lmer Article by Ben Ogorek Graphics by Bob Forrest Background My last article featured linear models with random slopes. For estimation and prediction, we used the lmer function from the lme4 package. Today we'll consider another level in the hierarchy, one...

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Visiting FHCRC, JHSPH and Meeting Xi’an

October 29, 2012
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Visiting FHCRC, JHSPH and Meeting Xi’an

I have been traveling during the last two weeks. I visited Fred Hutchinson Cancer Research Center on Oct 16 and the Department of Biostatistics at Johns Hopkins at the invitation of Simply Statistics on Oct 23. Today Christian Robert was visiting our department at Iowa State, and I also talked to him. It is really cool...

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