Monthly Archives: May 2010

Simulating a Queue in R

May 30, 2010
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Simulating a Queue in R

In the GCaP class earlier this month, we talked about the meaning of the load average (in Unix and Linux) and simulating a grocery store checkout lane, but I didn't actually do it. So, I decided to take a shot at constructing a discrete-event simulatio...

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Talk at CRiSM

May 30, 2010
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Talk at CRiSM

This is the talk I am giving at the workshop on model uncertainty organised by the Centre for Research in Statistical Methodology (CRiSM) at the University of Warwick, on May 30-June 1. Careful readers will notice there is not much difference with my previous talk on the topic, as I only included the Savage-Dickey slides

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Dynamic Modeling 2: Our First Substantive Model

May 30, 2010
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Dynamic Modeling 2: Our First Substantive Model

(This is the second of a series of ongoing posts on using Graph Algebra in the Social Sciences.) First-order linear difference equations are powerful, yet simple modeling tools.  They can provide access to useful substantive insights to real-world phenomena.  They can have powerful predictive ability when used appropriately.  Additionally, they may be classified in any number

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Notice that even though output is in a log scale, output is…

May 29, 2010
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Notice that even though output is in a log scale, output is…

Notice that even though output is in a log scale, output is shooting up in an exponential way. DATA from Brad DeLong

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Source Code Files in R

May 29, 2010
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Source Code Files in R

R's interactive programming style is similar to what I have seen in other environments (e.g. ruby's irb and Oracle's SQL*Plus, etc). There are a few commands that you need to be aware of to get up and running with developing R programs.To identify yo...

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Weekend art in R (part 1?)

May 29, 2010
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Weekend art in R (part 1?)

As usual click on the image for a full-size version. Code: par(bg="black") par(mar=c(0,0,0,0)) plot(c(0,1),c(0,1),col="white",pch=".",xlim=c(0,1),ylim=c(0,1)) iters = 500 for(i in 1:iters) { center = runif(2) size = rbeta(2,1,50)   # Let's create random HTML-style colors color = sample(c(0:9,"A","B","C","D","E","F"),12,replace=T) fill = paste("#", paste(color[1:6],collapse=""),sep="") brdr = paste("#", paste(color[7:12],collapse=""),sep="")   rect(center[1]-size[1], center[2]-size[2], center[1]+size[1], center[2]+size[2], col=fill, border=brdr, density=NA, lwd=1.5) }

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highlight 0.1-9

May 29, 2010
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The version 0.1-8 of highlight introduced a small bug in the latex renderer.This is now fixed in version 0.1-9 and the latex renderer also gains an argument "minipage" which wraps the latex code in a minipage environment. I've used this to make...

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Syncing files across computers using DropBox

May 29, 2010
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Syncing files across computers using DropBox

Motivation In the past few months I have been using DropBox for syncing my work files between my home and work computer. It has saved me from numerous mistakes and from sending the files to myself via e-mail. Recently I found this service highly useful for sharing files with 4 other people with whom I am working on a...

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An XML Representation of the Keys to Soil Taxonomy?

May 28, 2010
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An XML Representation of the Keys to Soil Taxonomy?

Western Fresno Soil Hierarchy: partial view of the hierarchy within the US Soil Taxonomic system Maybe this is just craziness, but wouldn't be neat to have an XML formatted version of the Keys to Soil Taxonomy? The format might look something like the ...

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R: More plotting fun with Poission

May 28, 2010
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R: More plotting fun with Poission

Coded as follows: x = seq(.001,50,.001) par(bg="black") par(mar=c(0,0,0,0)) plot(x,sin(1/x)*rpois(length(x),x),pch=20,col="blue")

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