LibSVM alpha vector

I am using LibSVM with java and I am getting correct classification results as I verified that with weka GUI. However, I want to get the alpha vector that results from the classification.

This is a snapshot of my code:

LibSVM svm = new LibSVM();

svm.buildClassifier(train_data);

Evaluation evaluation = null;

evaluation = new Evaluation (train_data);

evaluation.crossValidateModel(svm, train_data, 10, new Random(1));

Can anybody help me in getting the alpha vector please?