Page 63 - Introduction to Statistical Pattern Recognition
P. 63

2 Random Vectors and their Properties                         45



                                             Rnrxn  = BnixrCrxii  .           (2.169)

                    Since BTB is an r x rnonsingular matrix, C can be obtained by
                                            c = (B~B)-IB~R   .                (2.170)

                    From (2.170), C has rank r so that CCT is also an I'  x I' nonsingular matrix.  The
                    pseudoinverse R * of R is defined by

                                        R* = CT(CCT)-'(BTB)-'BT               (2.171)
                                                               .
                    It can be  shown that Rx satisfies (2.167)  and is therefore a generalized  inverse.
                    Further,  Rx is  unique.  The pseudoinverse is  the  most  often  used  generalized
                    inverse.

                    Standard Data and Experimental Procedure

                         Throughout this book the following data will be used:

                    Type of distribution:  normal,
                    Dimension: n = 8 unless specified otherwise,
                    Number of classes: L = 2,
                    Distribution parameters:

                              M, =O=[O.    017,  M*=M=[m1  ...


                                                                  0


                              z, =I=

                                                                  hR



                    Data 1-1:
                              ml =m,  m2= ... =mx=O,


                              1, = . . .  = h* = 1
                         In  this  data, both  C, and  C2 are 1. The value  of  m  controls the  overlap
                    between the two distributions.  Unless m (or .In/lTM or  IIMz -MI 1))  is specified
   58   59   60   61   62   63   64   65   66   67   68