Dear Jonathan,

Thanks so much for your very patient reply. I have one further question.

"During training, 3dsvm will automatically train a binary classifier for each class combination and only select the data (sub-bricks) belonging to that class combination (e.g. for the 1-vs-2 classifier, the sub-bricks belonging to all other classes (class-3,class-4) as well as sub-bricks labeled with 9999s will be ignored). During testing, the data will be sent through all binary classifiers and the class membership will be determined using a Directed Acyclic Graph (option: -DAG) or max votes wins (option: -vote)".

How should I define the classifier? Or should I just define this by the 1D data? For instance, I want to do the 1-vs-2 classifier, then I should list the 1D as below?

line 1: 9999
line 2-41: 1
line 42-80: 2
line 81-125: 9999
line 126-166: 9999
line 167: 9999

But according to your words "the sub-bricks belonging to all other classes (class-3,class-4) as well as sub-bricks labeled with 9999s will be ignored", my understanding is that I do not need set the "line 81-125: 3--> 9999; line 126-166: 4--> 9999". What is the secret?

Again, thank you very much,
Juan