Archive for March, 2010

SVM – support vector machines

Posted on the March 31st, 2010 under data mining,web mining by

SVM stands for support vector machines. The idea of this classification’ algorithm is generating border between objects that belong to different decision class. Big advantage of this approach is simple training set and moreover, it can be easy used to solve multi-dimensional problems. Line between objects is generated by iterative algorithm.

Types of SVM:

  • C-SVM
  • ni-SVM
  • regression epsilon SVM
  • regression ni-SVM

[http://www.spc.com.pl/textbook/stathome_stat.html?http%3A%2F%2Fwww.spc.com.pl%2Ftextbook%2Fstmachlearn.html]

decision trees

Posted on the March 15th, 2010 under data mining,definitions,general by

Classification and regression trees

Decision trees is one of the classification method – structures consisting nodes, connected with branches. Unlike the natural way, root appears on the top of the structure and branches go down ending with leaves or leading to another node.

Main goal of the algorithm is to select atributes (both whichever and sequence matter) to obtain highest conficence level. Decission trees fall under supervised learning category.

It is possible to employ classification trees, when:

  • training set with defined target variable exists
  • trainings set provides algorithm with representative group of records (enough examples)
  • discrete target variables

Bibl. [Daniel Larose ?Odkrywanie wiedzy z danych? 2006 PWN, 109, 111]