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...]

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 ... [Read more...]

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, 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 ... [Read more...]

I will assume you have read through part 1 and have the csv file loaded. While we covered some basic graphing in the last post i hope to get into a little more of the data crunching. Specifically I am interested in the names which where driven by a spe... [Read more...]

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Rob Hyndman has a great post on his blog with example on how to cross-validate a time series model.  The basic concept is simple:  You start with a minimum number of observations (k), and fit a model (e.g. an arima model) to those observation... [Read more...]

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After maintaining the  Quick-R website (R tutorials and jumpstart) for the past 5 years, I’ve decided to add a blog so that I can go into more detail on topics related to practical data analysis. The statMethods blog will contain articles … Continue reading → [Read more...]

Be careful if you have global daily data. The issue Markets around the world are open at different times.  November 21 for the Tokyo stock market is different from November 21 for the London stock market.  The New York stock market has yet a different November 21. The effect The major effect is ... [Read more...]

This is the first walk-through I have posted. Reading these types of posts has been incredibly helpful as I have been learning R and other useful tools in the Unix universe. Hopefully you find it helpful. First, I have been watching Google Python Video... [Read more...]

I’ve long searched for a somewhat efficient approach to indexing nested lists and/or environments and here’s my best solution so far. For me, being able to compute such an index is the crucial part in order to actually manage such nested structures (which are very helpful in ... [Read more...]

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I've been working on an example of the new Graph Template Language from SAS.  As I don't have direct access to SAS 9.2, I've been developing via email with a friend that does.In the meantime, I thought I would start to investigate some of the performance properties of R.  I ... [Read more...]

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When working with a tikz drawing within LaTeX document we might want to locate an object using an absoute position on the page rather than leaving LaTeX to make the decision for us. The use of nodes and the current.page label in conjunction with some other parameters attached to ... [Read more...]

A few days ago, Conrad Sanderson released the first pre-release version of what will be Armadillo 2.4.*, giving it the 2.3.91 release handle. We folded this into RcppArmadillo release 0.2.30, with Romain making a few adjustments to our template stru... [Read more...]

Hi! My fellow useRs! I’m making a web-based R Language platform ( http://cloudst.at/ ) for my students. My aim is to decrease the learning curve of learning R and collaboration. With CloudStat, there is no more download, installation, update and mai... [Read more...]

It is not uncommon to have two computers at work, four at home and a server out on the wild, wild internet (that's what we have, anyway ... wait, we forgot one in London). How to keep all these files in sync? Here are our file synchronization tips. [Read more...]

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