Dr. Alexander Pilhöfer

I now work as a Quantitative Analyst for Google Switzerland.
Contact me via Xing, LinkedIn or Facebook.

Alexander Pilhöfer


About me:

My PhD thesis 'Categorical Data Analysis Reordered' focussed on reordering and clustering techniques for nominal data as well as methods for visualization.

Further interests: Large datasets, interactive visual data analysis, conditional graphics, statistical modeling, classification and clustering techniques, dimension reduction techniques and graph theory

Some of the methodologies I developed for my PhD are available in my R-package: extracat


  • DAGStat Dortmund 2010: New approaches in visualization of categorical data: R-package extracat
  • DStatG Nachwuchsworkshop Nürnberg 2010: Graphical Analysis of categorical data
  • Data Technologies Seminar Augsburg 2010/2011: R: extensions and Interfaces
  • Statistical Computing Reisensburg 2011: optile: Optimizing k-dimensional graphical classifi cation analysis via category reordering
  • UseR! Warwick (UK) 2011: RMB: Visualising categorical data with Relative Multiple Barcharts
  • Participant at the Google Summer of Code 2011 (GSoC11) with the project "optile".
  • Visweek 2012 Seattle USA, Oct 14 - Oct 19: Talk "Comparing Clusterings Using Bertin's Idea"
  • Project with the Bavarian Environment Agency: A statistical analysis of the effects of the environmental zones on particulate matter concentration and air pollution.
  • Internship at the Institute of Biomathematics and Biometry located at the Helmholtz Research Centre Munich


Alexander Pilhoefer, Antony Unwin (2013). New Approaches in Visualization of Categorical Data: R Package
  extracat. Journal of Statistical Software, 53(7), 1-25. URL

Alexander Pilhofer, Alexander Gribov, Antony Unwin, Comparing Clusterings Using Bertin's Idea, IEEE Transactions on Visualization and Computer Graphics, vol. 18, no. 12, pp. 2506-2515, Dec., 2012

Antony Unwin, Tanja Hoegg, Alexander Pilhöfer (2011). "Agreeing to disagree: graphics for comparing expert classifications", Proc. 58th World Statistical Congress 2011, pp. 3273-3283, Dublin

R courses     

R Intro Slides (simple)
R Intro Slides II

new: R help galleries
RMB gallery

HEXPIE gallery

CPCP gallery

Steptile gallery

Personal interests



Sample selfmade graphics
(see also R help galleries above)