2702 search results for "gis"

RClimate Tools for Do It Yourself Climate Trend Analysis

August 31, 2010
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RClimate Tools for Do It Yourself Climate Trend Analysis

In this post I introduce my RClimate functions which allow R users to easily download and plot monthly temperature anomaly data for the 5 major global temperature anomaly data series: GISS, HAD, NOAA, RSS, UAH. Consolidated LOTA Data File In … Co...

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Even Simpler Multivariate Correlated Simulations

August 31, 2010
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Even Simpler Multivariate Correlated Simulations

So after yesterday’s post on Simple Simulation using Copulas I got a very nice email that basically begged the question, “Dude, why are you making this so hard?” The author pointed out that if what I really want is a Gaussian correlation structure for Gaussian distributions then I could simply use the mvrnorm() function from

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Stochastic Simulation With Copulas in R

August 30, 2010
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Stochastic Simulation With Copulas in R

A friend of mine gave me a call last week and was wondering if I had a little R code that could illustrate how to do a Cholesky decomposition. He ultimately wanted to build a Monte Carlo model with correlated variables. I pointed him to a number of packages that do Cholesky decomp but then

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Oh (de)bugger!

August 26, 2010
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Oh (de)bugger!

By number of questions asked, R passed MATLAB for the first time on Stack Overflow today. Thus it seems an appropriate time to write my first R-based post. This post concerns what to  do when your R-code goes pear shaped. Back in June there were a couple of very good videos on R debugging that

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Producing grids of plots in R with ggplot2: A journey of discovery

August 26, 2010
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Producing grids of plots in R with ggplot2: A journey of discovery

I’ve just gone through a bit of a ‘journey of discovery’ in R while trying to plot a grid of plots for one of the research projects I’m doing. I wanted to write a simple function which could produce this grid of plots from a CSV file, allowing me to easily view the trends of

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informality, the 2010 edition

August 24, 2010
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For the last two cycles I’ve done some simple regression analysis of the informal vote.  I saw Possum have his go at it, using a specification that is virtually the same as what I’ve run in the past (2007, 2004). The 2010 edition follows.  As usual, electorate-level informality in House of Reps voting increases with

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Webinar: Big Data Analysis with Revolution R

August 24, 2010
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Don't forget that I'll be hosting a webinar tomorrow talking about the new RevoScaleR package included with the forthcoming Revolution R Enterprise 4.0. The webinar will also feature a live demonstration from Joseph Rickert. The full details are below, and you can register for the webinar here. Big Data Analysis for R Using Revolution R Enterprise Date: Wednesday, Aug...

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GRASS Can Make Pretty Maps

August 23, 2010
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GRASS Can Make Pretty Maps

I have posted a couple examples in the past on the topic of high quality map production from GRASS GIS-- usually via the Generic Mapping Tools. I am not sure why, but I have previously avoided using the traditional cartographic output module that is bu...

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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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Using R for Introductory Statistics, Chapter 3.4

August 21, 2010
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Using R for Introductory Statistics, Chapter 3.4

...a continuing journey through Using R for Introductory Statistics, by John Verzani. Simple linear regression Linear regression is a kooky term for fitting a line to some data. This odd bit of terminology can be blamed on Sir Francis Galton, a proli...

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