June 2011

Cross de Bercy 2011 [v2&3]

June 10, 2011 | xi'an

[Warning: this post about a race I ran yesterday is unlikely to be of interest for most readers!] Following my (un)reasonable time last year, I registered again for the annual “Cross de Bercy”  run by the Sport Club of the Finance Ministry (with whom/which CREST is affiliated). This ... [Read more...]

What is ordisurf() doing…?

June 10, 2011 | Gavin L. Simpson

I’m writing this post for two reasons: i) someone searched on Google for the term ‘what is ordisurf doing’ and ended up on my blog, and ii) because I have been on the receiving end of reviewers comments on a paper I co-authored where they didn’t know what ... [Read more...]

Rejection Sampling

June 9, 2011 | tsperry

An interesting sampling method that was covered briefly in my Bayesian statistics course was rejection sampling. Since I have nothing better to do, I thought it would be fun to make an acceptance-rejection algorithm using R. FUN!The Rejection Sampling method is usually used to simulate data from an unknown ... [Read more...]

Image color palette replacement

June 9, 2011 | Marc in the box

Here is an example of a function I wrote to change the color palette used in an image. The above example comes from a black and white original, although color images can also be used. The function first converts the image to grayscale in order to have ...
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A Quantstrat to Build on Part 5

June 9, 2011 | klr

Another iteration of the quantstrat system but this time with a sum of standard deviations instead of simple count and then some comparison charts.  Thanks for the comments and I welcome many more.  In my head and it seems like in others base...
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Automating R Scripts on Amazon EC2

June 9, 2011 | Travis Nelson

Overview: How to setup R on an EC2 instance of Ubuntu 11.04 (Natty Narwhal) How to setup Apache Tomcat 6.0 web server and configuring it with basic authentication so that we can view our output from R on a password … Continue reading → [Read more...]

We are now a part of R-bloggers.com

June 9, 2011 | Ari F.

R-bloggers is a site that aggregates many of the best R blogs on the internet. We're glad they've allowed our R-related posts to be aggregated there. If you mainly write in R, it's worth checking them out. [Read more...]

R: Speeding things up

June 9, 2011 | Ari F.

R is many things, but it's not exactly speedy like a Patas Monkey. In fact, while it is much faster than many other solutions, R is notably slower than Stata (even inspiring talks that it should be rewritten from scratch!).Fortunately, Radford Neal ha... [Read more...]

New patches to speed up R 2.13.0

June 9, 2011 | Radford Neal

I have now released a new collection of 30 patches to speed up R version 2.13.0. You can get them here Assessing how much these patches speed up R is difficult. First of all, the speedup varies tremendously with the type of program. It also varies quite a bit with the machine ... [Read more...]

The R-Files: Jeroen Ooms

June 9, 2011 | David Smith

"The R-Files" is an occasional series from Revolution Analytics, where we profile prominent members of the R Community. Name: Jeroen Ooms Background: Ph.D. Candidate, Statistics, UCLA Nationality: Netherlands Years Using R: 3 1/2 Known for: Developing web applications for popular R packages including ggplot2, lme4, stockplot and irttool Jeroen Ooms is ... [Read more...]

Rotating disks

June 9, 2011 | xi'an

My neighbour is an half-retired entrepreneur who still runs his electric engine company. A few weekends ago, he came to me with the following physics question related with one of those engines: given a primary disk rotating at the angular speed of ω0 and a secondary disk located on the first ... [Read more...]

gridExtra – Multiple plots from ggplot2

June 8, 2011 | nzcoops

Thanks to this great post http://www.imachordata.com/?p=730 we can now put multiple plots on a display with ggplot2. This provides somewhat similar functionality to ‘par(mfrow=c(x,y))’ which would allow multiple plots with the base plot function. gridExtra doesn’t have quite the same level ... [Read more...]

vRoom vRoom : Speeding up R with C

June 8, 2011 | Milk Trader

Many times you don't want to trouble friends for help with menial tasks like moving furniture. But sometimes you need to step out and ask. Your friends are always happy to help, and after the heavy lifting is done you see how easy it can be. R likes to...
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Making Simple Packages in R on Windows

June 8, 2011 | Steven Mosher

There are any number of short tutorials on making add on R packages on your Windows machine. This is yet another version of that process. I’ve explained what I did in 10 easy steps on the pages, but I’ll give a brief overview here. In the first step I ... [Read more...]

A Quantstrat to Build on Part 4

June 8, 2011 | klr

When we build a system, we are almost always trying to beat buy and hold by some metric or metrics.  I have not found a demo to compare a quantstrat system with a generic buy and hold system.  Here is the way I accomplish a basic comparison w...
[Read more...]

A Quantstrat to Build on Part 3

June 8, 2011 | klr

This just does the same thing as A Quantstrat to Build on Part 2, but I use sigCrossover and sigComparison instead of sigThreshold as my signal.  Maybe it will help some struggling to understand implementation of the different signal types.  ...
[Read more...]

Real-time Analytics for Capital Markets with Revolution R

June 8, 2011 | David Smith

In the 2011 edition of the Sybase Capital Markets Guide, Revolution Analytics CTO David Champagne talks about the need for up-to-date analytics in Finance, and how you can integrate Revolution R with quality real-time data sources. Here's an excerpt: R represents a radically different approach to the challenges posed by analyzing ... [Read more...]
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