269 search results for "pca"

Principal Component Analysis (PCA) vs Ordinary Least Squares (OLS): A Visual Explanation

September 16, 2010
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Principal Component Analysis (PCA) vs Ordinary Least Squares (OLS): A Visual Explanation

Over at stats.stackexchange.com recently, a really interesting question was raised about principal component analysis (PCA). The gist was “Thanks to my college class I can do the math, but what does it MEAN?” I felt like this a number of times in my life. Many of my classes were focused on the technical implementations they kinda

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Using R and r.mapcalc (GRASS) to Estimate Mean Topographic Curvature

August 3, 2010
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Using R and r.mapcalc (GRASS) to Estimate Mean Topographic Curvature

Recently I was re-reading a paper on predictive soil mapping (Park et al, 2001), and considered testing one of their proposed terrain attributes in GRASS. The attribute, originally described by Blaszczynski (1997), is the distance-weighted mean differe...

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Tutorial: Principal Components Analysis (PCA) in R

May 20, 2010
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Found this tutorial by Emily Mankin on how to do principal components analysis (PCA) using R. Has a nice example with R code and several good references. The example starts by doing the PCA manually, then uses R's built in prcomp() function to do the s...

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Compcache on Ubuntu on Amazon EC2

May 4, 2010
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Compcache on Ubuntu on Amazon EC2

The following fully-automatic Bash script downloads, compiles, and initializes compcache version 0.6.2 on Ubuntu Karmic Koala (9.10). This script creates two swaps with a maximum of 4GB uncompressed size each. Two swaps are used to take advantage of 2 CPUs (or CPU cores in a multicore CPU). Compcache is a fascinating memory compression system. The

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Some R Highlights from the Bay Area Data Science Camp and Unconference

October 30, 2014
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Some R Highlights from the Bay Area Data Science Camp and Unconference

by Joseph Rickert The San Francisco Bay Area Chapter of the Association of Computing Machinery (ACM) has been holding an annual Data Mining Camp and "unconference" since 2009. This year, to reflect the times, the group held a Data Science Camp and unconference, and we at Revolution Analytics were, once again, very happy to be a sponsor for the...

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methylKit for bisulfite sequencing data analysis

October 21, 2014
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I have been relying upon methylKit, an R package for my RRBS data analysis. It is one the most highly cited R package for analysing bisulifite sequencing data. It is straight forward to install and it's vignette details all the major steps in the ...

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Twitter Pop-up Analytics

October 20, 2014
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Twitter Pop-up Analytics

IntroductionSo I've been thinking a lot lately. Well, that's always true. I should say, I've been thinking a lot lately about the blog. When I started this blog I was very much into the whole quantified self thing, because it was new to me, I liked the...

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Trying a prefmap

September 14, 2014
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Trying a prefmap

Preference mapping is a key technique in sensory and consumer research. It links the sensory perception on products to the liking of products and hence provides clues to the development of new, well tasting, products. Even though it is a key technique,...

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Mapping products in a space

September 7, 2014
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Mapping products in a space

I have read about people doing a Bayesian PCA at some points and always wondered how that would work. Then, at some point I thought of a way to do so. As ideas evolved my interest became not PCA as such, but rather in a prefmap. As a first step in that...

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Introducing H2O Lagrange (2.6.0.11) to R

September 1, 2014
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From my perspective the most important event that happened at useR! 2014 was that I got to meet the 0xdata team and now, long story short, here I am introducing the latest version of H2O, labeled Lagrange (2.6.0.11), to the R and greater data science communities. Before joining 0xdata, I was working at a competitor on a rival project and was repeatedly asked...

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