kernel.function calculates several kernel functions (uniform, triangle, epanechnikov, biweight, triweight, gaussian).
kernel.function(u, kernel = "normal", product = TRUE)n x d matrix
text string
or spherical kernel if d>1
matrix with diagonal elements set to x
slightly modified version of the kernel.function from the gplm package. The kernel parameter is a text string specifying the univariate kernel function which is either the gaussian pdf or proportional to (1-|u|^p)^q. Possible text strings are "triangle" (p=q=1), "uniform" (p=1, q=0), "epanechnikov" (p=2, q=1), "biweight" or "quartic" (p=q=2), "triweight" (p=2, q=3), "gaussian" or "normal" (gaussian pdf). The multivariate kernels are obtained by a product of unvariate kernels K(u_1)...K(u_d) or by a spherical (radially symmetric) kernel proportional to K(||u||). (The resulting kernel is a density, i.e. integrates to 1.)