February 2011

Weight Loss Predictor

February 5, 2011 | al3xandr3

Got for 2010 Xmas a very cool book called the "4 Hour Body"(thanks Jose Santos) written by Tim Ferriss who write a previous favorite of mine about productivity, the 4 hour work week. Its an interesting book, because it has a scientific approach, it ... [Read more...]

R: Colors

February 4, 2011 | Ari F.

"It ain't easy being green. ~ Kermit T. F. Matt Blackwell at the SSSB has made it easy to access all the Craylola(tm) colors in R.And in case you're not familiar with the way R handles color, here are a few resources:* The best color chart for R.* Colo... [Read more...]

Latent Gaussian Models in Zürich [day 1]

February 4, 2011 | xi'an

An interesting first day (for me) at the Latent Gaussian Models workshop in Zürich. The workshop is obviously centred at the INLA approach, with Havard Rue giving a short course on Wednesday then a wide ranging tour of the applications and extensions of INLA this afternoon. Thanks to his ... [Read more...]

Post-hoc Pairwise Comparisons of Two-way ANOVA

February 4, 2011 | andrew

I read this post today by John Quick. I was a little taken back when he used a pairwise t-test for post hoc analysis. In a contradiction the t-test did not show differences in the treatment means when the ANOVA model did. This is because the pairwise.t.test does ... [Read more...]

The R-Files: Dirk Eddelbuettel

February 4, 2011 | David Smith

"The R-Files" is an occasional series from Revolution Analytics, where we profile prominent members of the R Community. Name: Dirk Eddelbuettel Background: Ph.D. (EHESS, France), Quantitative Analyst Nationality: Canadian Years Using R: About 15 Known for: RQuantlib, Rcpp/RInside, R packaging for Debian/Ubuntu, Task Views for Finance and HPC, ... [Read more...]

Le Monde puzzle [#4]

February 4, 2011 | xi'an

A fairly simple puzzle in this weekend Le Monde magazine: given five points on a line such that their pairwise distances are 1,2,4,…,14,18,20, find the respective positions of the five points over the line and deduce the missing distances. Without loss of generality, we can set the first point at 0 and ... [Read more...]

Speed up your R code with C++

February 3, 2011 | Pierre Jacob

Hi again, Recently, Julyan blogged about allocating memory first before modifying R objects. That’s a very useful trick that applies to most programming languages. Tonight I want to blog about something a bit more complicated and more specific to R, but which can lead to massive speed-ups: interfacing C/...
[Read more...]

Regular expressions, an example

February 3, 2011 | Ari F.

Why regular expressions are your friend. This is written in Stata but applies to any language where regular expressions exist.Original version if length("`qx'")==3 { /*ex: 5q0*/ local a = substr("`qx'", 1, 1) local b = substr("`qx'", 3, 1) } else if substr("`qx'", 2, 1) == "q" & length("`qx'")==4 { /*ex: 5q20*/ local a = substr("`qx'", 1, 1) local b = ... [Read more...]

Mixed Models – Part 1

February 3, 2011 | nzcoops

Very brief. Have been exploring mixed models in R using nlme::lme. Am looking forward to understanding them more, they’re going to be used more and more in years to come I’ve no doubt of that. Here are some scripts, very rough, for diagnostics when running simple 2 levels, ... [Read more...]

R in production systems

February 2, 2011 | erehweb

R is great for prototyping models.  Not so great if those models have to run a business.  Here’s some tips to help with that: Validate, alert, and monitor Sink Use 64-bit Linux Write your own functions tryCatch Validate, alert, and monitor:  Sooner or later something is going to go ... [Read more...]

Fixing Up smoothScatter Heat Maps

February 2, 2011 | Millsy

A while back, I posted an article using the smoothScatter function in R that builds a color representation of density for scatter plots. When I first found the function, I was extremely excited because it's a very easy and automated way to make a heat... [Read more...]

Statistical Analysis with R Book Reviews

February 2, 2011 | John Quick

Reviews of my Statistical Analysis with R book have started to emerge online and I am writing today to share them with potential readers and recommenders. Reviews The following is a list of online reviews for Statistical Analysis with R. If you have w... [Read more...]

Charting For Fun

February 2, 2011 | MichaelDHealy

Interesting Charts Making Lemonade If you are working on the FREE eMetrics pass, and you really should if you need a free pass, I created some charts based on the sample data. These data are limited in terms of the … Continue reading →Charting For Fun is a post from: MichaelDHealy....
[Read more...]
1 8 9 10 11

Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)