2602 search results for "GIS"

Data Mining In Excel: Lecture Notes and Cases

July 10, 2012
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Data Mining In Excel: Lecture Notes and Cases

by Yanchang Zhao, RDataMining.com It is a 270-page book on data mining with Excel. It can be downloaded as a PDF file at http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.83.1393&rep=rep1&type=pdf. Below is its table of contents. - Overview of the Data Mining Process - Data Exploration … Continue reading →

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Sourcing Code from GitHub

July 10, 2012
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Sourcing Code from GitHub

In previous posts I described how to input data stored on GitHub directly into R. You can do the same thing with source code stored on GitHub. Hadley Wickham has actually made the whole process easier by combining the getURL, textConnection, and source commands into one function: source_url. This is in his devtools...

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Fitting a dynamic model, and determining the number of parameters that can be fitted.

July 8, 2012
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Fitting a dynamic model, and determining the number of parameters that can be fitted.

Let's suppose that we have the same dynamic model we presented before - that is, the Lorentz system of differential equations. Remember? In order to perform a fitting we need to define an objective function of sort: this will then be minimised. Now,...

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The Actuary Puzzle 508 – Square numbers

The Actuary Puzzle 508 – Square numbers

The Actuary Puzzle 508 - Square numbers Author: Matt Malin From the puzzle pages of The Actuary June 2012, I attempt to solve the following, making use of R: This square contains exactly 21 smaller squares. Each of these smaller squares has sides of integer length, with no two smaller squares having sides of the same length. Can you find a solution for...

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The R Journal Volume 4/1, June 2012

July 6, 2012
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As first reported by Paolo, the new R journal is out! You can Download the complete issue from here.  Refereed articles may be downloaded individually using the links below. Table of Contents Editorial 3   Contributed Research Articles   Analysing Seasonal Data  Adrian G Barnett, Peter Baker and Annette J Dobson 5 MARSS: Multivariate Autoregressive State-space...

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Error metrics for multi-class problems in R: beyond Accuracy and Kappa

July 6, 2012
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Error metrics for multi-class problems in R: beyond Accuracy and Kappa

The caret package for R provides a variety of error metrics for regression models and 2-class classification models, but only calculates Accuracy and Kappa for multi-class models.  Therefore, I wrote the following function to allow caret:::train t...

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Fix Overplotting with Colored Contour Lines

July 6, 2012
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Fix Overplotting with Colored Contour Lines

I saw this plot in the supplement of a recent paper comparing microarray results to RNA-seq results. Nothing earth-shattering in the paper - you've probably seen a similar comparison many times before - but I liked how they solved the overplotting...

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More Exploration of Crazy RUT

July 5, 2012
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More Exploration of Crazy RUT

Unintentionally while playing with the lawstat package in R, I started trying to build systems (STANDARD DISCLAIMER: NOT INVESTMENT ADVICE AND WILL LOSE LOTS OF MONEY SO PROCEED WITH CAUTION) based on the Jarque Bera test of normality (entry in Wikiped...

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The Higgs boson: 5-sigma and the concept of p-values

July 4, 2012
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The Higgs boson: 5-sigma and the concept of p-values

Why are physicists talking about 5-sigma, and what's it got to do with statistics? In this short post I'll explain what 5-sigma is and why it's not a measure of how certain scientist are that they've found the Higgs boson

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To the Basics: Bayesian Inference on A Binomial Proportion

July 4, 2012
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To the Basics: Bayesian Inference on A Binomial Proportion

Think of something observable – countable – that you care about with only one outcome or another. It could be the votes cast in a two-way election in your town, or the free throw shots the center on your favorite...

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