October 2011

Tomorrow: ACM Data Mining Camp at eBay

October 14, 2011 | David Smith

If you're in the Bay Area, tomorrow would be a great day to head down to San José for the ACM Data Mining Camp. Hundreds of data scientists, data hackers and data miners will be there for a fun "unconference", with talks and practical sessions organized on the spot according ... [Read more...]

Another Mystery: sas7bdat != sd2

October 14, 2011 | BioStatMatt

I received an email from a very inconvenienced statistician a few weeks ago. The problem was an old data file with the extension .sd2. Apparently, this is an obsolete data storage format used by past versions of SAS. A quick glance at the file contents revealed that this sd2 formatted ... [Read more...]

principles of uncertainty

October 13, 2011 | xi'an

“Bayes Theorem is a simple consequence of the axioms of probability, and is therefore accepted by all as valid. However, some who challenge the use of personal probability reject certain applications of Bayes Theorem.“  J. Kadane, p.44 Principles of uncertainty by Joseph (“Jay”) Kadane (Carnegie Mellon University, Pittsburgh) is a ... [Read more...]

plyr, ggplot2 and triathlon results, part II

October 13, 2011 | CL

I ended my previous post by mentioning how one could imagine other ways of looking at the triathlon data with plyr and ggplot2. I couldn’t help but carry on playing with it so here are more stats and graphs from … Continue reading → [Read more...]

System in 10 Minutes After Twitter

October 13, 2011 | klr

On Twitter last night, I spotted @milktrader from www.algorithmzoo.com doing some range research on equity indexes.  I offered a tweet on the crazy Russell 2000 17% move over 7 days.  Within 10 minutes, I discovered a signal that worked very ...
[Read more...]

Maximum likelihood

October 13, 2011 | Luis

This post is one of those ‘explain to myself how things work’ documents, which are not necessarily completely correct but are close enough to facilitate understanding. Background Let’s assume that we are working with a fairly simple linear model, where … Continue reading → [Read more...]

There’s a lot to like about R

October 13, 2011 | David Smith

I once heard John Chambers (the inventor of the S language, and member of the R Core Group) say, "Show me a programming language no-one complains about, and I'll show you a language no-one uses". The R language has its fair share of complainants, to be sure -- and that's ... [Read more...]

Waiting in line, waiting on R

October 13, 2011 | Matt Asher

I should state right away that I know almost nothing about queuing theory. That’s one of the reasons I wanted to do some queuing simulations. Another reason: when I’m waiting in line at the bank, I tend to do mental calculations for how long it should take me ... [Read more...]

Modelling with R: part 4

October 13, 2011 | MK

In part 3, we ran a logistic model to determine the probability of default of a customer. We also saw the outputs and tried to judge the performance of the model b plotting the ROC curve. Let's try a different approach today. How about a decision tree?... [Read more...]

Introduction to Asset Allocation

October 12, 2011 | systematicinvestor

This is the first post in the series about Asset Allocation, Risk Measures, and Portfolio Construction. I will use simple and naive historical input assumptions for illustration purposes across all posts. In these series I plan to discuss: Maximum Loss, MAD, CVaR, CDaR, Omega Risk Measures 130:30 Long/Short portfolios and ... [Read more...]

S&P 500 components heatmap in R

October 12, 2011 | enguyen

In this article, Hans Gilde exposes the clever use of a heatmap hidden in the Bioconductor library. In his example, he describes a way to show different ‘observations’ on subjects, with the concept of time. Financial indices, like the S&P 500 or the Dow Jones indices, are mathematically some kind ... [Read more...]

Typos in Introduction to Monte Carlo Methods with R

October 12, 2011 | xi'an

The two translators of our book in Japanese, Kazue & Motohiro Ishida, contacted me about some R code mistakes in the book. The translation is nearly done and they checked every piece of code in the book, an endeavour for which I am very grateful! Here are the two issues they ... [Read more...]
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