SPIDER The Spider Objects

Reduced set construction by C.Burges


   a = rsc_burges(alg,hyper)
   generates a rsc object, using the burges method
  
   hyperparameters:
   child=svm     algorithm worked on
   rsv=.5        if rsv e [0,1): #rsv = #sv * rsv
                 if rsv > 1: #rsv
   max_it=100    maximum of iterations for gradient descent
   eps=1e-5      epsilon
   phase2=yes    perform burges phase2 ?
   minimizer=1   (1) gradient descent (0) conj. gradient
   stv=3         number of restarts
   deriv='der_rbf' use function, which name is supplied as string, as
                 function to calculate d||w-w*||^2/dz_l
                 if set to 'num', usee numerical derivative instead
   
   model:
   alpha         new alphas for rs-vectors
   Xsv           rs vectors
  
   stats:
   w2=0          final value of ||w-w*||^2 
   delta_w=0     total decrease in ||w-w*||^2 
   dw=0          run through delta_w
  
   methods:
   train         constructs a reduced set, returns trained rs-machine
   test          tests new rs-machine on supplied data
  
   example:
   d=gen(toy2d('2circles','l=100'));
   [r,a]=train(svm({kernel('rbf',1),'C=10000','alpha_cutoff=1e-2'}),d);
   [r,a2]=train(rsc_burges(a,'rsv=.9'),d);
   test(a2,d,loss);
  
   author: chris burges
   reference: simplified sv decision rules, 1996