261 search results for "PCA"

How to Start Using (pgf)Sweave in LyX in One Minute

October 30, 2010
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regor Gorjanc published an interesting article “Using Sweave with LyX” in R News in 2008, which (I believe) makes it much easier to use Sweave. I use command-line tools a lot every day, but I am still “GUI-addicted”. (I don’t want to comment more about Microsoft Word here.) LyX is a somewhat WYSIWYG tool based

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Grabbing Tables in Webpages Using the XML Package

October 24, 2010
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ables are pretty common in web pages as data sources, and the most direct way to get these data is probably to copy and paste. This is OK if there are only two or three tables, and when we need to grab 5000 tables in 1000 web pages, we may not really wish to fulfill

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On the Gory Loops in R

October 17, 2010
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his blog post is mainly for Stat 579 students on the homework for week 7, since I received too many “gory” loops in the homework submissions and I think it would help a bit to write my thoughts on R loops for beginners. The immortal motto for newbies in programming is: If you want to

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SyntaxHighlighter Brush for the R Language

September 11, 2010
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al Galili requested in the R-help mailing list for a SyntaxHighlighter brush for the R language, so that WordPress users can highlight their R code easily. I promised to contribute a few minutes on this task, and here is the result: /** * Author: Yihui Xie * URL: http://yihui.name/en/2010/09/syntaxhighlighter-brush-for-the-r-language * License: GPL-2 | GPL-3 */

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Eigenimages: The AT&T Cambridge Faces Database

September 7, 2010
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Eigenimages: The AT&T Cambridge Faces Database

I picked up the AT&T Laboratories Cambridge database of faces for a clustering application. The database consists of images of 40 distinct subjects, each in 10 different facial positions and expressions. Typically, the goal of clustering in these data is to recover the ‘true’ partition, or that which isolates images of distinct subjects. Each image

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Global Temperature Proxy Reconstructions ~ now with CO2 forcing

August 26, 2010
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Global Temperature Proxy Reconstructions ~ now with CO2 forcing

Previously, I did a simple Bayesian projection of recent temperature using proxy data and the methods shown in McShane and Wyner (2010). I showed that when you take out the last 30 years of data (1969~1998), the projection does not track the recent uptick in temperatures well. The “projection” is a simple unparametric bootstrap which

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Global Temperature Proxy Reconstructions ~ Bayesian extrapolation of warming w/ rjags

August 22, 2010
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Global Temperature Proxy Reconstructions ~ Bayesian extrapolation of warming w/ rjags

Update: fixed projection. There are a bunch of “hockey sticks” that calculate past global temps. through the use of proxies when instrumental data is absent. There is a new one out there by McShane and Wyner (2010) that’s creating quite a stir in the blogosphere (here, here, here, here). The main take out being, that

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CoRe in CiRM [end]

July 17, 2010
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CoRe in CiRM [end]

Back home after those two weeks in CiRM for our “research in pair” invitation to work on the new edition of Bayesian Core, I am very grateful for the support we received from CiRM and through it from SMF and CNRS. Being “locked” away in such a remote place brought a considerable increase in concentration

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Chart the U.S. Gross National Product with the Federal Reserve API

June 17, 2010
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Chart the U.S. Gross National Product with the Federal Reserve API

The Federal Reserve of St. Louis has an amazing amount of economic data available through their API. You need to apply for an API key, and once you have been approved you include your API key as URL parameter to access your data. api_key='YOUR API KE...

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Clustergram: visualization and diagnostics for cluster analysis (R code)

June 15, 2010
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Clustergram: visualization and diagnostics for cluster analysis (R code)

About Clustergrams In 2002, Matthias Schonlau published in “The Stata Journal” an article named “The Clustergram: A graph for visualizing hierarchical and . As explained in the abstract: In hierarchical cluster analysis dendrogram graphs are used to visualize how clusters are formed. I propose an alternative graph named “clustergram” to examine how cluster members are assigned to clusters as...

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