map.xyz(): interpolation of XYZ data and projection onto a map

May 30, 2011
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map.xyz(): interpolation of XYZ data and projection onto a map

     I am still struggling to get a grasp of R's mapping capabilities. Part of my frustration lies in the fact that I often work on areas near the poles, which complicates interpolation across the 180 degree line. For smaller areas, interpolati...

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Legendre & Borcard: Nested ANOVA by Permutation

May 30, 2011
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Legendre & Borcard: Nested ANOVA by Permutation

..here's a very illustrative R-Script example by Legendre & Borcard showing how a Nested ANOVA can be done by permutation.Read more »

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Array position to matrix coordinates conversion

May 30, 2011
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Array position to matrix coordinates conversion

#A function that is sometimes useful in determining the #coordinate(i.e. row and column number) of a matrix position#(and vice-versa). #Either a vector of positions ("pos") #OR a 2 column matrix of matrix coordinates, ("coord", i.e. cbind(row,col)), #A...

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XLConnect 0.1-4

May 30, 2011
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XLConnect 0.1-4

Mirai Solutions GmbH (http://www.mirai-solutions.com) is pleased to release XLConnect 0.1-4. In the time since our first release (XLConnect 0.1-3, released on Feb 28, 2011) we received very positive and constructive feedback from the R community which heavily influenced the development … Continue reading →

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Searching for inaccurate literals in R

May 29, 2011
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Searching for inaccurate literals in R

In creating the numbers tool I wanted to be able to do two things, 1) obtain information about what source did by matching the numeric literals it contained against a database of ‘interesting’ values (now with over 14,000 entries) and 2) flag possible incorrect numeric literals (e.g., 3.1459265 when 3.14159265 had been intended in core/Helix.cpp

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R/Finance 2011 Presentations are online

May 29, 2011
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For those of you who don't subscribe to the R-SIG-Finance mailing list: You really should subscribe ;-)Dirk Eddelbuettel announced the R/Finance 2011 presentations are now available.I've included the entire announcement (with some hyperlinks) below.The organizing committee for the R/Finance 2011 conference is pleased to announce the availability of presentation slides from the 3rd annual R/Finance...

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R/Finance 2011 Presentations are online

May 29, 2011
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For those of you who don't subscribe to the R-SIG-Finance mailing list: You really should subscribe ;-) Dirk Eddelbuettel announced the R/Finance 2011 presentations are now available. I've included the entire announcement (with some hyperlinks) below.The organizing committee for the R/Finance 2011 conference is pleased to announce the availability of presentation slides from the 3rd annual R/Finance...

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googleVis-0.2.4 requires older version of RJSONIO (0.5-0) #rstats

May 29, 2011
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googleVis-0.2.4 requires older version of RJSONIO (0.5-0) #rstats

Downgrade to RJSONIO 0.5 if you want to be able to set initial states with the current googleVis package. Otherwise, there will be lots of extra backslashes in your JavaScript--and blank pages in your browser.

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Dicetributions – episode I

May 29, 2011
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Dicetributions – episode I

Suppose the following game with two players: In every round, the two players pick a random number, each. Instead of using a dice, they pick a number from an interval. Player A picks a number from and player B from . Variation 1. The greater number wins. Who is more likely to win? It

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R functions for Earth geographic coordinate calculations

May 29, 2011
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R functions for Earth geographic coordinate calculations

Here are some functions that I regularly use for geographic data (e.g. binning, filtering, calculation of new positions etc.).#distance in kilometers between two long/lat positions (from "fossil" package)earth.dist <- function (long1, lat1, long2, l...

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Which R documents to read, and which R packages to use

May 29, 2011
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Which R documents to read, and which R packages to use

There are lots of R documents and over 3000 R packages. Which documents to start with and which R packages to use are questions faced by many people. If you are new to R, an Introduction to R can be … Continue reading →

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Comparing HoltWinters() and ets()

May 29, 2011
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I received this email today: I have a question about the ets() function in R, which I am trying to use for Holt-Winters exponential smoothing. My problem is that I am getting very different estimates of the alpha, beta and gamma parameters using ets() compared to HoltWinters(), and I can’t figure out why. This is

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An Application of boot() to IV regression

May 28, 2011
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An Application of boot() to IV regression

Bootstrapping standard errors can be a useful technique when obtaining closed form for the standard error formula is difficult or intractable. In this post, I give an example of how to use R to create a bootstrap sampling distribution in the context o...

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An Application of boot() to IV regression

May 28, 2011
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An Application of boot() to IV regression

Bootstrapping standard errors can be a useful technique when obtaining closed form for the standard error formula is difficult or intractable. In this post, I give an example of how to use R to create a bootstrap sampling distribution in the context o...

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RcppArmadillo 0.2.21

Following up Conrad's 1.99.2 release (in RcppArmadillo 0.2.20), we now have Armadillo 1.99.3 en route to the upcoming 2.0.0 release. Armadillo is a templated C++ library for linear algebra---which RcppArmadillo brings to R based on our Rcpp library...

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R for the web

May 27, 2011
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There is a nice R module for apache: rApache. So you can easily publish statistics.

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Collaborative R coding using Dropbox

May 27, 2011
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Collaborative R coding using Dropbox

I do like Dropbox. I’m a big fan of easy to use solutions to common problems. For me I work at two different sites and I do a significant amount of work at my desktop machine at home as well as on my laptop. Dropbox solved the problem of synchronising files between

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Handling Errors Gracefully

May 27, 2011
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In R functions sometimes produces warnings or errors. In the case of errors execution of a function or a series of commands can get halted when an error occurs, which can in some cases be frustrating especially if we want to continue our calculations. There are various functions available in R for dealing with errors

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Norvig and the Nature of Modern Science

May 27, 2011
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In this, Chomsky is in complete agreement with O’Reilly. (I recognize that the previous sentence would have an extremely low probability in a probabilistic model trained on a newspaper or TV corpus.)1 Anyone who considers themself an intellectual should be required to read this new essay by Peter Norvig. It’s the best summary I’ve ever

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Presentations from R/Finance 2011 available

May 27, 2011
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Last month's R/Finance 2011 conference in Chicago was an outstanding event, bringing together some of the best minds in applying R to financial data. Presentations from the speakers are now available for download, with a wealth of useful information there for anyone working in quantiative finance. Not to be missed, though, is John Bollinger's (yes, that John Bollinger) retrospective...

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Notes to Self: Getting Rapache working in Natty Narwhal (Ubuntu/Linux)

May 27, 2011
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Notes to Self: Getting Rapache working in Natty Narwhal (Ubuntu/Linux)

In this post, I cover my experiences in getting Rapache working in the latest version of Ubuntu (11, Natty Narwhal). …Continue reading »

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Beginne..R 1.0

May 26, 2011
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Opening this blog is a step in a long journey of discovery, learning and frustration. To begin with I would consider myself a beginner R user, I am getting better, but I am not about to write a package any time soon. I started using R about three years...

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Beginne..R 1.0

May 26, 2011
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Opening this blog is a step in a long journey of discovery, learning and frustration. To begin with I would consider myself a beginner R user, I am getting better, but I am not about to write a package any time soon. I started using R about three years...

Read more »

Hammersley and Handscomb 1964 on line

May 26, 2011
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Hammersley and Handscomb 1964 on line

Through the webpage of the Advanced Monte Carlo Methods I & II, given a few years ago by Michael Mascagni at ETH Zürich, I found a link to the scanned version of the 1964 book Monte Carlo Methods by Hammersley and Handscomb. This is a short book, with less than 150 pages, especially if one

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Clustering with Currencies and Fidelity Funds

May 26, 2011
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Clustering with Currencies and Fidelity Funds

Great news came yesterday with the release of the R In Finance 2011 Presentations.  I must attend next year after seeing all that I missed.  The Iacus: Statistical Analysis of Financial Time Series and Option Pricing in R (pdf) presentation o...

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New online R courses from Statistics.com

May 26, 2011
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Online training provider Statistics.com has introduced a couple of new R-related courses which are well worth checking out. These are all self-paced on-line courses, with materials by and interactive feedback from leading R gurus. Current R users looking to take their programming skills to the next level will be particularly interested in the Advanced Programming in R course from...

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another look at CRAN Task Views

May 26, 2011
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another look at CRAN Task Views

We've been impressed with how helpful the CRAN Task Views are in guiding us in R as we wend our way through the huge number of add-on packages (3021 as of May, 2011). These are web pages that are maintained by volunteers with expertise in a specified ...

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Simple pattern detection in numerical data

May 26, 2011
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A while ago I helped out a colleague who was testing some methods to detect economic (in)activity of companies, based on their quarterly tax declarations (our institute has access to such data). One of the thing my colleague wanted was to detect simple patterns, … Continue reading →

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Simple pattern detection in numerical data

May 26, 2011
By
Simple pattern detection in numerical data

A while ago I helped out a colleague who was testing some methods to detect economic (in)activity of companies, based on their quarterly tax declarations (our institute has access to such data). One of the thing my colleague wanted was t...

Read more »