对k()进行变换有： 1,if data pointx lies inside a cube of side h centered on x, 0,otherwise. The total number of data points lying inside the cube: K=产) =1 From: px)= K NV V=hD where D is the dimension of the hypercube V of side h. We get: 12/27▶ 对 k(u) 进行变换有： k( x − xn h ) =    1, if data point xn lies inside a cube of side h centered on x, 0, otherwise. ▶ The total number of data points lying inside the cube: K = ∑ N n=1 k( x − xn h ) ▶ From: p(x) = K NV , V = h D where D is the dimension of the hypercube V of side h. ▶ We get: p(x) = 1 N ∑ N n=1 1 h D k( x − xn h ), 12 / 27