SPIDER The Spider Objects

Multi-class Support Vector Machine by J.Weston


   A=MC_SVM(H) returns an mc_svm object initialized with hyperparameters H. 
  
    Multi-class Support Vector Machine, solving a single
    optimization problem.
  
   Hyperparameters, and their defaults
    C=Inf                -- the soft margin C parameter
    child=kernel         -- the kernel is stored as a member called "child"
   
   Model
    alpha                -- the weights
    b0                   -- the threshold
    Xsv                  -- the Support Vectors
  
   Methods:
    train, test, get_w  
  
   Example:
   
   c1=[-1,1];c2=[1,1];c3=[0,-1];
   
   X1= randn(50,2)+repmat(c1,50,1);
   X2= randn(50,2)+repmat(c2,50,1);
   X3= randn(50,2)+repmat(c3,50,1);
     note the class label format!
   Y1= [ones(50,1),-ones(50,1),-ones(50,1)];
   Y2= [-ones(50,1),ones(50,1),-ones(50,1)];
   Y3= [-ones(50,1),-ones(50,1),ones(50,1)];
   
   d=data([X1;X2;X3],[Y1;Y2;Y3]);
   
   [r,a]=train(mc_svm(kernel('rbf',2)),d)
     Test class centers
   dtest=data([c1;c2;c3]);
   rtest=test(a,dtest)
   plot(a);

Reference : Multi-class Support Vector Machines
Author : Jason Weston, Chris Watkins
Link : http://citeseer.ist.psu.edu/8884.html