Monthly Archives: December 2011

Call for Abstracts for useR! 2012

December 24, 2011
By

The international R User Conference useR! 2012 will be held June 12-15 at Vanderbilt University in Nashville, Tennessee, USA, with a pre-conference full-day course offered on June 11. Participants are encouraged to submit a one-page abstract for oral or poster presentation at the conference. Half-day tutorials will be held in the morning and afternoon of June 12th. For tutorials,...

Read more »

ML-Class Ex 7 – kMeans clustering

December 24, 2011
By
ML-Class Ex 7 – kMeans clustering

The K-means algorithm is a method to automatically cluster similar data examples together.The intuition behind K-means is an iterative procedure that starts by guessing the initial centroids, and then refines this guess by repeatedly assigning examples to their closest centroids and then recomputing the centroids based on the assignments.Read more »

Recology is 1 yr old

December 23, 2011
By
Recology is 1 yr old

This blog has lasted a whole year already.  Thanks for reading and commenting.There are a couple of announcements:Less blogging: I hope to put in many more years blogging here, but in full disclosure I am blogging for Journal of Ecology now, ...

Read more »

Recology is 1 yr old

December 23, 2011
By
Recology is 1 yr old

This blog has lasted a whole year already.  Thanks for reading and commenting.There are a couple of announcements:Less blogging: I hope to put in many more years blogging here, but in full disclosure I am blogging for Journal of Ecology now, ...

Read more »

Recology is 1 yr old…

December 23, 2011
By
Recology is 1 yr old…

This blog has lasted a whole year already.  Thanks for reading and commenting. There are a couple of announcements:Less blogging:  I hope to put in many more years blogging here, but in full disclosure, I am blogging for Journal of Ecology no...

Read more »

A Christmas Miracle

December 23, 2011
By

Data files on 407 banks, between the dates of 2007 to 2009, on the daily borrowing with the US Federal Reserve bank. The data sets are available from Bloomberg at this address data This is an unprecedented look into the day-to-day transactions of ...

Read more »

Programming traps when using "sample"

December 23, 2011
By
Programming traps when using "sample"

Standard sample function works differently when it gets single element integer vector as opposed to longer vectors. This can lead to unexpected bugs in R code.Several times I had a problem with code similar to one given here:for (i in 1:4) {&...

Read more »

Norman Nie on two big problems with Big Data

December 23, 2011
By

Revolution Analytics CEO Norman Nie sat down with Cassimir Medford from Business Agility to talk about the problems business today face with respect to Big Data. The two big problems identified: finding adequately trained personnel and locating the right tools. Norman traces the problem of finding skilled practitioners to work with Big Data to the US educational system: The...

Read more »

Portfolio Optimization in R, Part 4

December 23, 2011
By
Portfolio Optimization in R, Part 4

This post will conclude the portfolio optimization series.  In this post, we will construct a trading strategy based on portfolio optimization and test the results against the CAPM market portfolio as well as another strategy.It is worth reiterati...

Read more »

googleVis 0.2.13: new stepped area chart and improved geo charts

December 23, 2011
By
googleVis 0.2.13: new stepped area chart and improved geo charts

On 7th December Google published a new version of their Visualisation API. The new version adds a new chart type: Stepped Area Chart and provides improvements to Geo Chart. Now Geo Chart has similar functionality to Geo Map, but while Geo Map requires ...

Read more »