rcage (version 1.2)

radial: Gaussian Radial Basis Functions

Description

Provides an implementation of the Gaussian radial basis functions defined as $$ \Psi_{j}(s) = \exp\{- \frac{1}{2} (||s - c_j||/w)^2\}.$$

Usage

radial(crd, knots, w = NULL, ..., longlat = TRUE)

Arguments

crd

A matrix object. The (x,y) coordinates of the reference points {nCrd x 2}.

knots

A matrix object. The (x,y) coordinates of the knots {r x 2}.

w

A numeric object. The positive scaling factor (bandwidth).

...

ignored. Included only to require naming of inputs that follow.

longlat

A logical object. If FALSE, Euclidean distance is calculated; if TRUE, Great Circle distance is calculated. See ?sp::spDists for more information.

Value

A matrix of Gaussian functions evaluated at all combinations of crd and knots { nCrd x r }.

Details

Distances between reference coordinates and knots are obtained using sp::spDists().

Examples

# NOT RUN {
  data(countyExample)

  radial(crd = sp::coordinates(county), knots = knots)

# }