SPIDER The Spider Objects

KNN k-nearest neighbours object


   a = knn(hyperParam)
   
   Generates a knn object with given hyperparamters.
  
   Hyperparameters (with defaults)
    k=1                  -- number of neighbours
    batch=1              -- true if to be computed in batch 
                             (requires more memory)
    child=kernel;        -- kernel function (distances computation/ 
                             default is linear kernel)
    output_preimage=0    -- whether output index from training sample 
                             of preimage 
                            instead of actual label
  
   Model
    dat                  -- data used for neighbours computation
  
   Methods:
    train, test
   c1=[2,0];
   c2=[-2,0];
   X1=randn(50,2)+repmat(c1,50,1);
   X2=randn(50,2)+repmat(c2,50,1);
   d=data([X1;X2],[ones(50,1);-ones(50,1)]);
   [r,a]=train(cv(knn({kernel('poly',3),'k=3'})),d);   use knn with 3 number of neighbours and polynomial kernel order 3
   loss(r)

Reference : chapter 4 (Richard O. Duda and Peter E. Hart) k-nearest neighbor
Author : Richard O. Duda , Peter E. Hart
Link : http://www.amazon.com/exec/obidos/tg/detail/-/0471056693/002-6279399-2828812?v=glance