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

You can always reduce a multi-class classification problem to a binary problem by choosing random partititions of the set of classes, recursively. This is not necessarily any less effective or efficient than learning all at once, since the sub-learning problems require less examples since the partitioning problem is smaller. (It may require at most a constant order time more, e.g. twice as long). It may also lead to more accurate learning.

I'm not necessarily recommending this, but it is one answer to your question, and is a general technique that can be applied to any binary learning algorithm.