How to do multi class classification using Support Vector Machines (SVM)

Question

In every book and example always they show only binary classification (two classes) and new vector can belong to any one class.

Here the problem is I have 4 classes(c1,

Answer 1

Commonly used methods are One vs. Rest and One vs. One. In the first method you get n classifiers and the resulting class will have the highest score. In the second method the resulting class is obtained by majority votes of all classifiers.

AFAIR, libsvm supports both strategies of multiclass classification.