May 2, 2011
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## Introducing R in the Enterprise

May 2, 2011
By

We've introduced R in the organization!It is running along with the heavy weights of statistical analysis like SAS, SPSS, Matlab. Here's what we did and how we did it...HOW DID IT START?I started learning R last year and loved its simplicity and power....

## Introducing R in the Enterprise

May 2, 2011
By

We've introduced R in the organization!It is running along with the heavy weights of statistical analysis like SAS, SPSS, Matlab. Here's what we did and how we did it...HOW DID IT START?I started learning R last year and loved its simplicity and power....

## Review of the R Cookbook

May 2, 2011
By

While we were at R/Finance in Chicago over the weekend (more on that later), it was a great pleasure to meet in person Paul Teetor, author of the R Cookbook (published by O'Reilly). If you haven't picked it up yet, I recommend checking it out: if you already have a basic familiarity of the R syntax, but want to...

## R/Finance conference in Chicago – April 29, 2011 to April 30, 2011

May 2, 2011
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This was my first year to attend the R/Finance conference that focuses on the use R programming in applied finance.  I was unable to get out there until mid-morning on Friday, so I missed Jeff Ryan’s tutorial on Automated Trading … Continue reading →

## Oscar awards: good actor versus good actress

May 2, 2011
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I am not a big fan of those ceremonies, where some actors pretend that they are extremely happy to be there, and then some win a trophy, some don't, and those who win start to cry, and those who did not get a trophy try to pretend that they are not...

## Unicode symbols in R

May 2, 2011
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A friend asked me this morning if there was a way to plot a symbol in R (as a plotting character) representing a half-filled circle. I didn't know, but I figured this out (perhaps it's demonstrated elsewhere -- the ability to use Unicode symbols was added in 2008 or so -- but I didn't stumble across it). First, looking...

## Unicode symbols in R

May 2, 2011
By

A friend asked me this morning if there was a way to plot a symbol in R (as a plotting character) representing a half-filled circle. I didn't know, but I figured this out (perhaps it's demonstrated elsewhere -- the ability to use Unicode symbols was added in 2008 or so -- but I didn't stumble across it). First, looking...

## Home Away From Home

May 2, 2011
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It used to be stuffed animals everywhere. These days, it's those annoyingly small lego pieces. Toys in the house have a certain Tribble quality to them. They propagate during some designated time in the middle of the night and in the morning, they are ...

## Sustainable Futures conference in Manchester

Recently, Kevin Ummel gave a short conference about his PhD research at the Sustainable futures – Tyndall Centre researchers’ international conference. His work, named “Optimizing worldwide deployment of wind and solar power technologies via a high resolution, linear programming model”, is built with R. He is using the solaR package for the solar irradiance calculations,

## Postdoc on adaptive MCMC in Paris

May 2, 2011
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Although the official deadline is long past, I just became aware of this call for a postdoctoral position in Paris starting next Fall. Please feel free to apply: Summary Adaptive Markov Chain Monte Carlo (MCMC) methods are currently a very active field of research. MCMC methods are sampling methods, based on Markov Chains which are

## Day #32-33 reporting, R and Birt

May 2, 2011
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I’m starting on my real R-Scripts now. We got an assesment for some Reports and they needed my graphs and Veerle’s Reports. So the tasks are: Well distribution plot Quality plate control Surface Plot Heatmap CirclePlot and more to come&#823...

## Building R packages for Windows when you don’t use it.

May 2, 2011
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Are you a non-windows user wanting to share your R package with others who do use windows? There's a handy utility (http://win-builder.r-project.org/)that allows you to upload your .tar.gz file and it checks it, builds it, and sends you a link to downl...

## Building R packages for Windows when you don’t use it.

May 2, 2011
By

Are you a non-windows user wanting to share your R package with others who do use windows? There's a handy utility (http://win-builder.r-project.org/)that allows you to upload your .tar.gz file and it checks it, builds it, and sends you a link to downl...

## "Inside" Functors — Evaluating things more than once

May 1, 2011
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(The examples here work with the version of insidefunctor tagged as "v1") I ran into an interesting problem using "inside" functors. Something is wrong in the following code (well, depending on what you thought it should do). > library(insidefunctor) > %+.% = fmap(+) > x = seq(0, 10, len = 50) > plot(x,...

## The R Inferno revised

May 1, 2011
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Hell is new and improved. The R Inferno has been revised.  If you don’t know of it, it is a short explanation of a few trouble spots when using the R language.  Somehow the short explanation grew to approach book-length. It can be found at the usual place: http://www.burns-stat.com/pages/Tutor/R_inferno.pdf Major improvements An index has been … Continue reading...

## Here comes the sun

The solar irradiance incident outside the earth’s atmosphere is called the extraterrestial or extra-atmospheric irradiance. It is derived from the solar constant only with geometric equations. It can be easily calculated with the calcSol function of the solaR package. With this post I will show an example with some packages from the Spatial task view.

## Bayesian Confidence Intervals: Obama’s ‘That’-Addition and Informality

May 1, 2011
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$Bayesian Confidence Intervals: Obama’s ‘That’-Addition and Informality$

No “That” Left Behind? I came across a post on Language Log last week giving some evidence that Obama tends to add that to the prepared version of his speeches. For example, in a recent speech at George Washington University, … Continue reading →

## Some rediscovered R scripts from spring cleaning

May 1, 2011
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Gompertz Model Visualization # Gomperz growth function gomp <- function(x, a, b, k) a*exp(-b*exp(-k*x))   # Normal model with Gompertz mean function likelihood <- function(weight, age, sigma, a, b, k) { mu <- gomp(age, a, b, k) dnorm(weight, mu, sigma) }   # Visualize the model visualize <- function(phi=40, theta=-35) { weight <- seq(0, 250,

## Schelling’s Neighborhood Model

April 30, 2011
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The New York Times has created a beautiful visualization of the Census Bureau's 2005-2009 American Community Survey data. The distribution of racial and ethnic groups in New York City is particularly fascinating:Chinatown appears in red toward the sou...

## Produce Authentic Math Formulas in R Graphics

April 30, 2011
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I remember a few weeks ago, there was a challenge in the R-help list to make the prime symbol in R graphics. In LaTeX, we simply write $X'$ or $X^\prime$. R has a rough support for math expressions (see demo(plotmath)) and they are certainly unsatisfactory for LaTeX users. In fact we can write native LaTeX

April 30, 2011
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About a year ago I was reading Godel, Escher, Bach by Douglas Hofstadter. In a section on recursion he presents a sequence that he calls "A Chaotic Sequence" defined as:Q(n) = Q(n - Q(n - 1)) + Q(n - Q(n - 2)) for n > 2Q(1) = Q(2) =1It's sim...

## Visualizing Terrain Surface Indicies with Scaled Arrows

April 30, 2011
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Hamish Bowman recently posted a new GRASS module (d.barb) that can be used to depict the direction and magnitude components of some vector (e.g. wind field) along a raster surface or at points in space. An example (c/o Hamish): read more

## Bootstrap Confidence Intervals for Diversity Indices

April 30, 2011
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Here's the bootstrap refinement of the normal asymptotic interval (Mills and Zandvakili, 1997; Dixon et al., 1987; Efron and Tibshirani, 1997) - where Diversity (div, g) is the Simpson Index calculated from the observed sample, k is the number boot...

## Produce Authentic Math Formulas in R Graphics

April 30, 2011
By

I remember a few weeks ago, there was a challenge in the R-help list to make the prime symbol in R graphics. In LaTeX, we simply write $X'$ or $X^\prime$. R has a rough support for math expressions (see demo(plotmath)) and they are certainly unsatisfac...

## Friday function triple bill: with vs. within vs. transform

April 29, 2011
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When you first learnt about data frames in R, I’m sure that, like me, you thought “This is a lot of hassle having to type the names of data frames over and over in order to access each column”. library(MASS) anorexia$wtDiff <- anorexia$Postwt - anorexia\$Prewt #I have to type anorexia how many times? Indeed, any

## Another Use of LSPM in Tactical Portfolio Allocation

April 29, 2011
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After the slightly unconventional use of LSPM presented in Slightly Different Use of Ralph Vince’s Leverage Space Trading Model, I thought I should follow up with something that more closely resembles my interpretation of Ralph Vince’s book. LSPM s...

## Rcpp Workshop slides

April 29, 2011
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Dirk and I gave a full day Rcpp workshop yesterday in Chicago before the R in Finance conference. The pdfs of the slides are available here: part 1 (intro), part 2 (details), part 3 (modules) and part 4 (applications)