Page 260 - Introduction to Statistical Pattern Recognition
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242                        Introduction to Statistical Pattern Recognition


















                                                                                 (5.168)


                      where


                                                                                 (5.169)

                                                                               ,.*
                           Quadratic  classifier:  When  a  quadratic  classifier  is  used,  h  (X)  in
                      (5.169) becomes
                                                  ,,*  ,,*    ** r*
                                      h*(X) =f(X,M,,Z,) -f(X,M2A),               (5.170)
                                                                         ,.*     ,.=
                      wheref(.,.,.) is defined in (5.143).  The bootstrap parameters, Mi, and Z, , are


                                                                                 (5.171)


                                                                                 (5.172)

                                                       ,.*                A’
                      Note that h, = (X~~iX~))/N, instead of  M,  is used to compute E,. In the con-
                      ventional sample covariance matrix, the sample mean  is used, because the true
                                                                                  A
                      expected  vector  is  not  available.  However,  the  true  expected  vector,  M,, is
                                                                            ,.x
                      available in the bootstrap operation, and the use of M, instead of  M,  simplifies
                      the discussion significantly.  Their expectations are
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