2774 search results for "GIS"

Dynamical systems: Mapping chaos with R

July 13, 2012
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Dynamical systems: Mapping chaos with R

Chaos. Hectic, seemingly unpredictable, complex dynamics. In a word: fun. I usually stick to the warm and fuzzy world of stochasticity and probability distributions, but this post will be (almost) entirely devoid of randomness. While chaotic dynamics are entirely deterministic, their sensitivity to initial conditions can trick the observer into seeing iid. In ecology, chaotic

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Health Care Costs – Part 2, "Unhealthy Things Not Related to the Problem"

July 11, 2012
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Health Care Costs – Part 2, "Unhealthy Things Not Related to the Problem"

Lighting Up Way back in the day, folks believed that smoking was not only cool but also completely safe. As Marcel Danesi states in his book Of Cigarettes, High Heels, and Other Interesting Things, Second Edition: An Introduction to Semiotics ...

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2nd CFP: the 10th Australasian Data Mining Conference (AusDM 2012)

July 10, 2012
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2nd CFP: the 10th Australasian Data Mining Conference (AusDM 2012)

The Tenth Australasian Data Mining Conference (AusDM 2012) Sydney, Australia, 5-7 December 2012 http://ausdm12.togaware.com/ The Australasian Data Mining Conference has established itself as the premier Australasian meeting for both practitioners and researchers in data mining. This year’s conference, AusDM’12, co-hosted … Continue reading →

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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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