Page 311 - Introduction to Statistical Pattern Recognition
P. 311

6  Nonparametric Density Estimation                           293




                                                                                (6.151)

                     then the basis function of (6.141) becomes

                                                                                (6.152)

                     where


                                                                                (6.153)

                     which is the normalized y,.
                          On the other hand, the kernel of  (6.142) becomes

                                                                                (6.154)

                     If the y, 's are mutually independent, p (Y) becomes equal to K(Y).

                          Thus, we can find the expansion of p (Y) as

                                                                                (6.155)

                     where  the first term K(Y)  equals p (Y)  under the independence assumption, and
                     all other terms of  [.] are the correction terms.  The cj's are calculated by

                                                                                (6.156)

                     Thus, (6.155) becomes





                     where y's  are the correlation coefficients of the associated variables.

                                                                                (6.158)
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