Monthly Archives: November 2011

Volume by Price Charts using R

November 23, 2011
By
Volume by Price Charts using R

R-Bloggers is a wonderful site which offers some great ideas for analysis.While I have been busy of late, hence could not do much with R, I was inspired by this post by Eric Nguyen on Volume by Price chart. This chart can be used with a great effe...

Read more »

Why we need to deal with big data in R

November 22, 2011
By

Responding to the birth rates analysis in the post earlier this week on big-data analysis with Revolution R Enterprise, Luis Apiolaza asks at the Quantum Forests blog, do we really need to deal with big data in R? My basic question is why would I want to deal with all those 100 million records directly in R? Wouldn’t it...

Read more »

Misleading Statistics: Too much risk without a financial adviser?

November 22, 2011
By
Misleading Statistics: Too much risk without a financial adviser?

This popular article references a report by financial consulting firms that makes a fairly convincing argument (even though they mostly neglect inferential statistics, and some parts of their argument are misleading, or otherwise not convincing) that 401(k) participants who accept "help" from financial experts take less risk and have better returns than those who do

Read more »

Magical RUT with GIST

November 22, 2011
By
Magical RUT with GIST

In search of better ways to post my R code, I finally discovered how GIST can help make my R blogging easier.  I know I am way behind, and I apologize to my loyal readers for my shortcomings.  Here is yesterday’s Magical Russell 2000 code u...

Read more »

Time series cross-validation 2

November 22, 2011
By
Time series cross-validation 2

In my previous post, I shared a function for parallel time-series cross-validation, based on Rob Hyndman's code.  I thought I'd expand on that example a little bit, and share some additional wrapper functions I wrote to test other forecasting&nbsp...

Read more »

Example 9.15: Bar chart with error bars ("Dynamite plot")

November 22, 2011
By
Example 9.15: Bar chart with error bars ("Dynamite plot")

The "dynamite plot", a bar chart plotting the a mean with a error bar, is one of the most reviled types of image among statisticians. Reasons to dislike them are numerous, and are nicely summarized here. (Edward Tufte also suggests they be avoided.) ...

Read more »

Do we need to deal with ‘big data’ in R?

November 22, 2011
By
Do we need to deal with ‘big data’ in R?

David Smith at the Revolutions blog posted a nice presentation on “big data” (oh, how I dislike that term). It is a nice piece of work and the Revolution guys manage to process a large amount of records, starting with … Continue reading →

Read more »

Sermon Sentiment Analysis

November 22, 2011
By
Sermon Sentiment Analysis

Matt Chandler vs. Mark Driscoll I came across an interesting API from Viral Heat which is capable of “Sentiment Analysis.” This analysis is designed to capture the sentiment of a statement by ranking it on a scale from -1 to 1. For instance, a chipper sentence like “The smell of roses makes me giddy!” is

Read more »

RPostgreSQL 0.2-0, 0.2-1 and an unsung Open Source hero

November 21, 2011
By

RPostgreSQL goes back to a topic suggestion I had made for the Google Summer of Code 2008, and specifically for the R Project participation that year. And Sameer Kumar Prayaga (whom I then mentored for the project) did a fine job that summer putting t...

Read more »

Revolution R Enterprise 5.0 now available for free academic download

November 21, 2011
By

Revolution R Enterprise 5.0, which we announced last week, is now available for free download to students and faculty at academic institutions worldwide. If you've downloaded Revolution R Enterprise via the academic program before and are on the mailing list, you will have already received an email with download instructions; if not, just complete the form linked below and...

Read more »