Under construction - (A selection of random things)

Interesting books

  • "Information is beautiful"


Interesting charts

  • FB relationships and betweenness-centrality fb2.pdf


Interesting programs

  • vowpal wabbit (online machine learning)
  • cplex (combinatorial optimization)
  • porta (integer polytope analysis)
  • tesseract (low level ocr)
  • postscript (the postfix-notation programming language)


Interesting paradoxes

  • Mathematical
    • Braess : How adding an additional road (at a badly selected place) increases capacity, but can make traffic worse (non optimal Nash equilibrium).
    • Newcomb : Intuitively correct versus obviously correct: when a problem is (deliberately) ambiguously underspecified.
    • Simpson : Treatment A is better than B for group 1, and also separately for group 2, but the inverse is correct for groups 1 and 2 combined. Can made to happen easily by adding imbalance between the two groups for each treatment.
    • Harmonic mean : People use the average for situations where the correct way is to use the harmonic mean. The harmonic is the correct way to average km/hour, miles per hour, dollars per kilo, miles per litre (gallon) etc, because in reality, one ought to be averaging (with the arithmetic mean) the hours/km, hours per mile, kilos per dollar, and litres or gallons per mile.
    • Benford 
    • Friendship
  • Computer science
    • A limitation of floating number precision
  • NLP related
    • Selection of difficult or ambiguous phrases for NLP processing