February 2010

How to use mcsm

February 27, 2010 | 0 Comments

Within the past two days, I received this email Dear Prof.Robert I have just bought your recent book on Introducing Monte Carlo Methods with R.  Although I have checked your web page for the R programs (bits of the code in the book, codes for generating the figures and ...
[Read more...]

Be Careful Searching Python Dictionaries!

February 27, 2010 | 0 Comments

For my talk on High Performance Computing in R (which I had to reschedule due to a nasty stomach bug), I used Wikipedia linking data, an adjacency list of articles and the articles to which they link. This data was linked from DataWrangling and was originally created by Henry Haselgrove. ... [Read more...]

An interesting paper

February 27, 2010 | 0 Comments

Ben Bolker has an interesting paper (outline of a paper) comparing different approaches to estimate GLMM in R environment, which is very helpful to what I am doing right now.The paper pointed out the following options to fit GLMM using R:glmerglmmMLglm...
[Read more...]

oro.dicom 0.2.4

February 26, 2010 | 0 Comments

The R package oro.dicom is a major revision, and improvement, on the previous package DICOM.  New features include Increased speed Uploading only header information (for restricted memory) Reading implicit value representations (VR's) Parsing SequenceItem tags (undefined lengths are allowed) Integration with oro.nifti to convert DICOM to NIfTI Provided ... [Read more...]

Steve Miller on R at Predictive Analytics World

February 26, 2010 | 0 Comments

At the Information Management blog, Steve Miller has provided two great reviews (here and here) of last week's Predictive Analytics World conference, including a recap of the Bay Area User's Group meeting featuring John Chambers. (My personal highlight from John's talk? A photograph of the very first sketch of what ... [Read more...]

Because it’s Friday: Visualizing an email chain

February 26, 2010 | 0 Comments

We've all been there: someone sends an email to a mailing list with a Reply-To directing responses back to the mailing list. Before long, someone replies (unwittingly, to everyone) to ask to be taken of the list. And before long, the entire affair devolves into an endless cycle of requests ... [Read more...]

R tip: Finding the location of minimum and maximums

February 26, 2010 | 0 Comments

I can never remember this R command, so I am going to post it here which probably means I will always remember it and never have to look it up here again.I sometimes want to find the location of a minimum or maximum value in a vector, so I ... [Read more...]

R and Sudoku solvers: Plus ca change…

February 25, 2010 | 0 Comments

Christian Robert blogged about a particularly heavy-handed solution to last Sunday's Sudoku puzzle in Le Monde. That had my symapthy as I like evolutionary computing methods, and his chart is rather pretty. From there, this spread on to the REvolutions blogs where David Smith riffed on it, and showed the ... [Read more...]

Welcome, Robin!

February 25, 2010 | 0 Comments

Robin Ryder started his new blog with his different solutions to Le Monde puzzle of last Saturday (about the algebraic sum of products…), solutions that are much more elegant than my pedestrian rendering. I particularly like the one based on the Jacobian of a matrix! (Robin is doing a postdoc ... [Read more...]

Responding to the Flowingdata GDP Graph Challenge

February 25, 2010 | 0 Comments

Nathan Yau of Flowingdata put up a challenge earlier today to improve upon a graph showing government spending as a percentage of GDP, published in the Economist. The underlying data wasn’t available. So I put on my graph-to-numbers glasses on and pulled out some data. Here it is in ...
[Read more...]

Solving Sudoku with Simulated Annealing

February 25, 2010 | 0 Comments

How long would it take you to solve this devlishly hard Sudoku puzzle (from Le Monde)? You could do it the old-fashioned way -- with a pencil -- but Xi'an decided to solve it by programming a simulated annealing solver in R. The algorithm works by first guessing a solution ... [Read more...]

inkblot: an alternative to stacked bar graphs

February 25, 2010 | 0 Comments

Sometimes it is not easy to get useful information from a stacked bar chart, see for instance this blogpost at Support Analytics.So-called inkblot charts, as discussed at Kaiser Fung's Junk Charts, allow the reader to focus on the evolution of a time series.Now how to make this kind ... [Read more...]

Interaction plot from cell means

February 24, 2010 | 0 Comments

I needed to produce a few a interaction plots for my book in R and, while the interaction.plot() function is useful it has a couple of drawbacks. First, the default output isn't very pretty. Second, it works from the raw data, whereas I often need plot... [Read more...]

ggplot2: Plotting Dates, Hours and Minutes

February 24, 2010 | 0 Comments

Plotting timeseries with dates on x-axis and times on y-axis can be a bit tricky in ggplot2. However, with a little trick this problem can be easily overcome. Let’s assume that I wanted to plot when the sun rises in London in 2010. sunriset function in maptools package calculates the ... [Read more...]

PoRtable…

February 24, 2010 | 0 Comments

Jobless as I might be, I do have some clients for data analysis. I try not to visit them in their office coz then things get really slow and time-consuming. When I can’t escape this, the worst thing is tuning data and software with client. So, I have a ...
[Read more...]

Object types in R: The fundamentals

February 24, 2010 | 0 Comments

If you're a self-taught R programmer, you've probably grappled with the different kinds of objects you can use in the language. When should you use a list instead of a vector? What's the difference between a factor and character vector? These questions are easier to answer when you have some ... [Read more...]

SoilWeb iPhone App: Beta-Testers?

February 23, 2010 | 0 Comments

iPhone App Screenshot rev 0.2 - icon iphone App Screenshot rev 0.2 - in Fresno   More Updates: The application is now available on the Apple iTunes Store. Preliminary documentaion here. read more
[Read more...]
1 2 3 7

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)