2610 search results for "gis"

Experiments with igraph

April 21, 2010
By
Experiments with igraph

Networks – social and biological – are all the rage, just now. Indeed, a recent entry at Duncan’s QOTD described the “hairball” network representation as the dominant cultural icon in molecular biology. I’ve not had occasion to explore networks “professionally”, but have always been fascinated by both networks and the tools used to analyse them.

Read more »

Simulating Dart Throws in R

April 16, 2010
By

Back in November 2009 Wired wrote an article about some grad students who decided to try to stochastically model throwing darts. Because I don’t actually read printed material I didn’t see the article until a couple of months ago. My immediate thought was, “hey, I drink beer. I throw darts. I build stochastic models. Why

Read more »

An article attacking R gets responses from the R blogosphere – some reflections

April 16, 2010
By
An article attacking R gets responses from the R blogosphere – some reflections

In this post I reflect on the current state of the R blogosphere, and share my hopes for the future

Read more »

R is an Epic Fail?

April 15, 2010
By

I came across this blog post just now: The Next Big Thing, and of course these words caught my attention: However, for me personally and for most users, both individual and organizational, the much greater cost of software is the time it takes to install it, maintain it, learn it and document it. On

Read more »

I’d be more than happy with the unlinked data web

April 14, 2010
By
I’d be more than happy with the unlinked data web

Visit this URL and you’ll find a perfectly-formatted CSV file containing information about recent earthquakes. A nice feature of R is the ability to slurp such a URL straight into a data frame: quakes <- read.csv("http://neic.usgs.gov/neis/gis/qed.asc", header = T) colnames(quakes) # "Date" "TimeUTC" "Latitude" "Longitude" "Magnitude" "Depth" # number of recent quakes nrow(quakes) #

Read more »

Cherry Picking to Generalize ~ NASA Global Temperature Trends ~ enhanced w/ ggplot2

April 12, 2010
By
Cherry Picking to Generalize ~ NASA Global Temperature Trends ~ enhanced w/ ggplot2

In a prior article, I tried to visualize the linear global temperatures trends for a grid of start and end years. The visual I created was confusing in that the specification of color scale was interdependent with the data values. I wanted a blue -> white -> red scale of the temperatures indicating cool ->

Read more »

REvolution R Community 3.2 now available

April 9, 2010
By

REvolution R Community, REvolution's free distribution based on R from the R Project, has been updated to version 3.2 and is now available for download for Windows and MacOS. Some features of this release include: Upgraded R engine. This release is based on R 2.10.1, the latest release (as of this writing). This brings many new features to the...

Read more »

GLMM using DPpackage

April 9, 2010
By
GLMM using DPpackage

I was able to fit a semi-parametric Bayesian GLMM model using DPpackage. It took me many hours to sample from the posterior distribution (DPM prior):MCMC scan 1000 of 5000 (CPU time: 18950.080 s)MCMC scan 2000 of 5000 (CPU time: 22510.100 s)M...

Read more »

Cherry Picking to Generalize ~ NASA Global Temperature Trends

April 6, 2010
By
Cherry Picking to Generalize ~ NASA Global Temperature Trends

The relatively (to this decade) cool 2008 global temperatures spurred talks of a warming pause, or even global cooling. The claim usually comes from people who cherry picked either data sets and(!)/or start and end points of the global temperature trends to back up their allegation. The blogosphere already has a lot on this: Skeptical

Read more »

Le Monde rank test

April 4, 2010
By
Le Monde rank test

In the puzzle found in Le Monde of this weekend, the mathematical object behind the silly story is defined as a pseudo-Spearman rank correlation test statistic, where the difference between the ranks of the paired random variables and is in absolute value instead of being squared as in the Spearman rank test statistic. I don’t

Read more »