Weka is a collection of machine learning algorithms for data mining tasks. The algorithms can either be applied directly to a dataset or called from your own Java code. Weka contains tools for data pre-processing, classification, regression, clustering, association rules, and visualization. It is also well-suited for developing new machine learning schemes.

A possible way of doing this is:

  • From the Weka installation unzip the weka-src.jar (or you can use cvs download too) into a folder named Weka. Put this folder in the eclipse workspace.
  • Then create a new project called Weka (Eclipse will detect the files).

Look at http://www.cs.waikato.ac.nz/~ml/weka/eclipse_and_weka/ for step-by-step description with screen snap shots.

Source: Weka FAQ