Making Sense of Large Piles of Soils Information: Soil Taxonomy

May 27, 2009
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Making Sense of Large Piles of Soils Information: Soil Taxonomy

Western Fresno Soil Hierarchy: partial view of the hierarchy within the US Soil Taxonomic system   Soil...

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Embeding fonts in figures produced by R

May 27, 2009
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Some publishers insist that we embed (include) the fonts in each figure. Here is a set of links regarding this issue for figures produced by R:http://tolstoy.newcastle.edu.au/R/help/05/01/10779.htmlhttps://stat.ethz.ch/pipermail/r-help/2006-October/114...

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Embeding fonts in figures produced by R

May 27, 2009
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Some publishers insist that we embed (include) the fonts in each figure. Here is a set of links regarding this issue for figures produced by R:http://tolstoy.newcastle.edu.au/R/help/05/01/10779.htmlhttps://stat.ethz.ch/pipermail/r-help/2006-October/114...

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R and data

May 26, 2009
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R and data

My fellow bloggers John and Scott have posted recently about the free statistical programming language R.  How does it compare to an expensive language like SAS? If you’ve done any statistical analysis, then you’ll know that getting and cleaning the data is a major step in any project.  SAS does a pretty good job at

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Free one-day R course at Vanderbilt

May 26, 2009
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The Vanderbilt Kennedy Center is offering a free (repeat, free) one-day introductory course to the R statistical computing language on June 23, taught by Theresa Scott from the department of Biostatistics. You can find contact/registration info at the link below.Vanderbilt Kennedy Center - An Introduction to the Fundamentals & Functionality of the R LanguageIn case you missed it,...

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More Recursion in R

May 26, 2009
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I found another gem in R today. Earlier I commented about how R could do recursion, something that I love. I write some pretty complicated recursion functions in my research, but I also have a bad habit of compulsively reorganizing things. Now I've c...

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Simple Approach to Converting GRASS DB-backends

May 23, 2009
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  Premise: The current default database back-end used by the GRASS vector model is DBF (as of GRASS 6.5), however this is probably going to be changed (to SQLite) in GRASS 7. The DBF back-end works OK, however it tends to be very sensitive (i.e. breaks) when reserved words occur in column names or...

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Temporary Debian mail outage

May 23, 2009
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It would appear that debian.org rejected mail for maybe up to twelve hours from late yesterday afternoon (Central timezone) to some time shortly after I got up this morning. Things appear to be back to normal, so a big Thanks to the mail admins. If yo...

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Temporary Debian mail outage

It would appear that debian.org rejected mail for maybe up to twelve hours from late yesterday afternoon (Central timezone) to some time shortly after I got up this morning. Things appear to be back to normal, so a big Thanks to the mail admins. If you happened to have sent me mail to my debian.org address during that time period, you may have...

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Data.gov

May 21, 2009
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Data.gov

I am always on the lookout for useful data sources for training in statistics, so I am excited that Data.gov has opened for business. The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the US Government.

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Data.gov

May 21, 2009
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Data.gov

I am always on the lookout for useful data sources for training in statistics, so I am excited that Data.gov has opened for business. The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the US Government.

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Bootstrapping and the boot package in R

May 21, 2009
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Bootstrapping and the boot package in R

I was recently asked about options for bootstrapping. The following post sets out some applications of bootstrapping and strategies for implementing it in R.I've found bootstrapping useful in several settings:where the statistic I'm interested in is a ...

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Baby steps with RSRuby in Rails

May 20, 2009
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Baby steps with RSRuby in Rails

Plotting and charting libraries for Ruby (on Rails) abound. However, few are sophisticated enough for scientists and many are not actively maintained. Plotting in R, on the other hand, is about as sophisticated as it comes. Can we bridge Ruby and R? Yes we can, thanks to Alex Gutteridge’s RSRuby. The next

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Create multiple graphics in R without multiple calls to pdf / postscript / jpeg / png

May 14, 2009
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To save multiple graphics, e.g, Rplot001.pdf, Rplot002.pdf, …, Rplot050.pdf, we don’t have to call pdf() 50 times (or any similar function). Use “Rplot%03d.pdf” for filename in pdf() and each plot() call will be saved to a new pdf file. Use dev.off() once at the end to close all devices! check out ?sprintf for more information

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Nonparametric High-Dimensional Time Series Analysis

Functional Gradient Descent (FGD) is a method of nonparametric time series analysis, useful in particular for estimating conditional mean, variances and covariances for very high-dimensional time series. FGD is a kind of hybrid of nonparametric statis...

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Negative Scalability Coefficients in Excel

May 12, 2009
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Negative Scalability Coefficients in Excel

Recently, several performance engineers, who have been applying my universal scalability law (USL) to their throughput measurements, reported a problem whereby their Excel spreadsheet calculations produced a negative value for the coherency parameter (...

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Packages featured with Inference for R

May 12, 2009
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Packages featured with Inference for R

quantmod, TTR, and xts were (not so) recently featured on the Inference for R Blog. Inference for R is a Integrated Development Environment (IDE) designed specifically for R.The post gives an example of how to easily perform advanced financial stock a...

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Analytic Infrastructure – Three Trends

May 11, 2009
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This is a post about systems, applications, services and architectures for building and deploying analytics. Sometimes this is called analytic infrastructure. In this post, we look at several trends impacting analytic infrastructure. Trend 1. Open source analytics has reached Main Street. R, which was first released in 1996, is now

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Analytic Infrastructure – Three Trends

May 11, 2009
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Analytic Infrastructure – Three Trends

This is a post about systems, applications, services and architectures for building and deploying analytics. Sometimes this is called analytic infrastructure. In this post, we look at several trends impacting analytic infrastructure. Trend 1. Open source analytics has reached Main Street. R, which was first released in 1996, is now

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Analytic Infrastructure – Three Trends

May 11, 2009
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Analytic Infrastructure – Three Trends

This is a post about systems, applications, services and architectures for building and deploying analytics. Sometimes this is called analytic infrastructure. In this post, we look at several trends impacting analytic infrastructure. Trend 1. Open source analytics has reached Main Street. R, which was first released in 1996, is now

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vim plugin for R

May 11, 2009
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vim plugin for R

For the vim/R-addicted a must to have: http://www.vim.org/scripts/script.php?script_id=2628

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Searching through mailing list archives

May 8, 2009
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Searching through mailing list archives

Romain Francois on his blog posted a very useful function to search through the R mailing list archives. Take a look at it here. Take also a look at the tm package introduced in  R News, 8(2):19–22, Oct. 2008 with an example dealing with analysi...

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Region Of Interest analysis of BOLD data

Region Of Interest analysis of BOLD data

For my research I do Region-Of-Interest (ROI) analyses of BOLD fMRI data. That is, we look at how brain activity develops in certain predefined brain regions during an experiment. On this site I describe a script that automates these analyses, using SP...

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Resources for Learning R in Iraq?

May 6, 2009
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Resources for Learning R in Iraq?

Please comment on this if you know of Arabic and Kurdish language resources for learning R. I have been encouraging the economics faculty here to learn R for econometrics, both on grounds of quality and cost. Here is a short list of resources that can help new users make the transition from SPSS if they

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SNA with R: Loading large networks using the igraph library

May 6, 2009
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SNA with R: Loading large networks using the igraph library

We are interested in Social Network Analysis using the statistical analysis and computing platform R. The documentation for R is voluminous but typically not very good, so this entry is part of a series where we document what we learn as we explore the tool and the packages. In our previous post on SNA we gave up...

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R Reference Card (PDF)

May 5, 2009
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Last week I posted a short tutorial on how to merge datasets using R. R is a free and open-source statistical computing software and programming language (get R here). The only downside is a steeper learning curve because the documentation is sparse and often difficult to understand at first. Once you start using it, you'll realize...

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05.05.09: 6 Steps to call a C function in R

May 5, 2009
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TasksWrap for netMotifsSubmit Abstract for PhD RetreatRead Architecture paperÖzgür's WST data and Uli's RTCA dataAfter some searching and testing, I have began to know how to call a C function in R. The reason for doing this can be speed (for example, the convolution of two finite sequences, as raised by the Writing R Extensions tutorial, refered as...

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R/Finance 2009 Presentations Online

May 4, 2009
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R/Finance 2009 Presentations Online

Posted to the R-SIG-Finance mailing list today:For those who missed it, the slides for the R/Finance 2009 tutorialsand presentations are now available on RinFinance.comhttp://www.RinFinance.com/presentationsWe want to thank everyone who traveled to Chi...

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Colouring a 3D plot according to z-values

May 3, 2009
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Colouring a 3D plot according to z-values

Here is a script that colors a 3D plot according to the z value (height) of each point. persp.withcol <- function(x,y,z,pal,nb.col,...,xlg=TRUE,ylg=TRUE) { colnames(z) <- y rownames(z) <- x nrz <- nrow(z) ncz <- ncol(z) color <- pal(nb.col) zfacet <- z + z + z + z facetcol <- cut(zfacet, nb.col) par(xlog=xlg,ylog=ylg)

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