400 search results for "evaluation"

Breaking the rules with spatial correlation

January 7, 2013
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Breaking the rules with spatial correlation

Students in any basic statistics class are taught linear regression, which is one of the simplest forms of a statistical model. The basic idea is that a ‘response’ variable can be mathematically related to one or any number of ‘explanatory’ variables through a linear equation and a normally distributed error term. With any statistical tool,

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Infinite generators in R

January 5, 2013
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Infinite generators in R

This is first in a series of posts about creating simulations in R. As a foundational discussion, I first look …Continue reading »

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Twitter Roundup, January 4 2013

January 4, 2013
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I've said it before: Twitter makes me a lazy blogger. Lots of stuff came across my radar this week that didn't make it into a full blog post. Here's a quick recap:PLOS Computational Biology: Chapter 1: Biomedical Knowledge IntegrationAssuring the quali...

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R code and data for book “R and Data Mining: Examples and Case Studies”

January 2, 2013
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R code and data for book “R and Data Mining: Examples and Case Studies”

R code and data for book “R and Data Mining: Examples and Case Studies” are now available at http://www.rdatamining.com/books/rdm/code. An online PDF version of the book (the first 11  chapters only) can also be downloaded at http://www.rdatamining.com/docs. Below are its … Continue reading →

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Using apply, sapply, lapply in R

December 18, 2012
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This is an introductory post about using apply, sapply and lapply, best suited for people relatively new to R or unfamiliar with these functions. There is a part 2 coming that will look at density plots with ggplot, but first I thought I would go on a tangent to give some examples of the apply family, as they...

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Matrix Algebra Useful for Statistics

December 16, 2012
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Matrix Algebra Useful for Statistics

I was having a conversation with an acquaintance about courses that were particularly useful in our work. My forestry degree involved completing 50 compulsory + 10 elective† courses; if I had to choose courses that were influential and/or really useful they would be Operations Research, Economic Evaluation of Projects, Ecology, 3 Calculus and 2 Algebras.

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Multisite, multivariate genetic analysis: simulation and analysis

December 13, 2012
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Multisite, multivariate genetic analysis: simulation and analysis

The email wasn’t a challenge but a simple question: Is it possible to run a multivariate analysis in multiple sites? I was going to answer yes, of course, and leave it there but it would be a cruel, non-satisfying answer. … Continue reading →

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Bridge hand distribution: simulation vs exact calculation

December 8, 2012
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Bridge hand distribution: simulation vs exact calculation

Recently I played bridge with my friends. Being frustrated with several consecutive poor hand distributions we asked ourselves a question what is the probability of having a hand good enough for a small slam. A well known rule of thumb is that you need...

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Function Closures and S4 Methods

December 4, 2012
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Function Closures and S4 Methods

This brief tutorial illustrates how to combine S4 object oriented capabilities with function closures in order to develop classes with built in methods. Thanks to Hadley Wickham for the great contribution of material and tutorials made available on the web and to Bill Venables and Stefano Iacus for their kind reviews. Regular … Continue reading →

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Data types part 4: Logical class

November 30, 2012
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Data types part 4: Logical class

First, an update:  A commentator has asked me to post my code so that it is easier to practice the examples I show here.  It will take me a little bit of time to get all of my code for past posts well-documented and readable, but I have uploa...

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