SAMME - Multiclass AdaBoost
@author: Jia Geng
SAMME  is a multi-class adaboost algorithm.
# set up parameters, e.g 500 weak learners and 5 classes num_learner = 500 num_cats = 5 # prepare your data. need to be in the following format # if your data are image and the image arrays are too larger to be put into list # you can modify the src code so that it takes img file id and make it read the image file online train_data = [(X, label), (X, label), (X, label), ...] # put your weak learner into a list. your weak learner need to have a `.predict(X) -> label` method # if not, you need to modify the src code to make it compatible weak_learners = [wl1, wl2, ...] # construct the booster instance booster = SAMME(num_learner, num_cats) # train the booster booster.train(train_data, weak_learners) # make prediction prediction = booster.predict(X)
11/02/19: Implement the main methods. Still need to test.
11/03/19: Added a small number to prevent possible divide by zero case
 Zhu, Ji & Rosset, Saharon & Zou, Hui & Hastie, Trevor. (2006). Multi-class AdaBoost. Statistics and its interface. 2. 10.4310/SII.2009.v2.n3.a8.