Monthly Archives: April 2013

Dynamic Wrapping and Recursion with Rcpp

April 8, 2013
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Dynamic Wrapping and Recursion with Rcpp

We can leverage small parts of the R’s C API in order to infer the type of objects directly at the run-time of a function call, and use this information to dynamically wrap objects as needed. We’ll also present an example of recursing through a list.To get a basic familiarity with the main functions exported from R API, I...

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Next Kölner R User Meeting: 12 April 2013

April 8, 2013
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Next Kölner R User Meeting: 12 April 2013

Quick reminder: The next Cologne R user group meeting is scheduled for this Friday, 12 April 2013. We will discuss cluster analysis and shiny. Further details and the agenda are available on our KölnRUG Meetup site. Please sign up if you would like to come along. Notes from the last Cologne R user group meeting are...

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analyze the pesquisa nacional por amostra de domicilios (pnad) with r

April 7, 2013
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think of the pesquisa nacional por amostra de domicilios (pnad) as the brazilian census for off-years - the ones that don't end in zero.  the principal household survey for the nation of brazil, pnad measures general education, labor, income, and ...

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Dirichlet Process, Infinite Mixture Models, and Clustering

April 7, 2013
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Dirichlet Process, Infinite Mixture Models, and Clustering

The Dirichlet process provides a very interesting approach to understand group assignments and models for clustering effects.   Often time we encounter the k-means approach.  However, it is necessary to have a fixed number of clusters.  Often we encounter situations where we don’t know how many fixed clusters we need.  Suppose we’re trying to identify

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A quick guide to non-transitive Grime Dice

April 7, 2013
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A quick guide to non-transitive Grime Dice

A very special package that I am rather excited about arrived in the mail recently. The package contained a set of 6-sided dice. These dice, however, don’t have the standard numbers one to six on their faces. Instead, they have assorted numbers between zero and nine. Here’s the exact configuration: Aside from maybe making for

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Venue Recommendation – A Simple Use Case Connecting R and Neo4j

April 7, 2013
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Venue Recommendation – A Simple Use Case Connecting R and Neo4j

Last month I attended the CeBIT trade fair in Hannover. Besides the so called “shareconomy” there was also another main topic across all expedition halls - Big Data. This subject is not completely new and I think that a lot of you also have experiences with some of the tools associated with Big Data. But due to the great...

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Mastering Matrices

April 7, 2013
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Mastering Matrices

R has many ways to store information.  Most of the time, our data comes in the form of a dataset, which we bring into R as a data.frame object. However, there are times when we want to use matrices as well. This post will show you how matrices can...

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Sync

April 7, 2013
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Sync

I am listening to the audiobook Sync: How Order Emerges from Chaos in the Universe, Nature, and Daily Lifeby Steven Strogatz which I got from Audible. Obviously a mathematical book is not ideal to listen to, but lacking illustrations I can ma...

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Travis CI for R?

April 7, 2013
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Travis CI for R?

I'm always worried about CRAN: a system maintained by FTP and emails from real humans (basically one of Uwe, Kurt or Prof Ripley). I'm worried for two reasons:the number of R packages is growing exponentially; time and time again I see frustrations ...

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Guide to accessing MS SQL Server and MySQL server on Mac OS X

April 6, 2013
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Native GUI client access to MS-SQL and MySQL We can use Oracle SQL Developer with the jTDS driver to access Microsoft SQL Server. Note: jTDS version 1.3.0 did not work for me; I had to use version 1.2.6. Detailed instructions can be found here. We can use MySQL Workbench to access MySQL server. Setup is... Read more »