parzen_normal.m

模式识别中Parzen窗函数的实现

%window function: Normal distribution func
%
% (C)2008 TangSheng
% 
%---------正态分布窗函数------------%
function parzen_normal(XX,YY,ZZ,Xi,n,nn,h1)
hn = h1/sqrt(n);
Vn = hn*hn;                                    %超立方体体积
for i = 1:sqrt(nn)
    for j = 1:sqrt(nn)
        ZZ(i,j) = 0;                           %Z轴坐标初始化为0
    end
end
        
for i = 1:sqrt(nn)
    for j = 1:sqrt(nn)
          sum = 0;
        for k =1:n
            u = sqrt((XX(i,j)-Xi(k,1))^2+(YY(i,j)-Xi(k,2))^2);%估计点与距离
            sum =sum+(1/sqrt(2*pi))*exp(-0.5*u.^2);           %窗函数的累加
        end
        ZZ(i,j) = sum/n;                       %获得Z轴个坐标上的值
    end
end
mesh(XX,YY,ZZ);                                %通过坐标(X,Y,Z)绘出估计的3-D概率密度图形
name = ['Parzen正态窗估计：','N=',num2str(n),', h1=',num2str(h1)];
title(name);
end