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RadialBasis: kernel values (linear, cubic, quintic, thin-plate, polyharmonic, multiquadric family, Gaussian, Wendland). RbfInterpolate: interpolation or smoothing in any dimension with polynomial augmentation and optional anisotropic transform. RbfLoocv: Rippa leave-one-out errors per shape parameter. RbfMultiscale: multiscale Wendland residual fitting. RbfGrid: grid evaluation. Identical to the Python arm morie.fn.rbfsurf.

Usage

RadialBasis(r, kernel = "thin_plate", epsilon = 1, order = 3, support = 1)

RbfInterpolate(
  X,
  y,
  Xnew,
  kernel = "thin_plate",
  epsilon = 1,
  degree = 1,
  smoothing = 0,
  order = 3,
  support = 1,
  transform = NULL
)

RbfLoocv(X, y, epsilons, kernel = "gaussian", degree = -1, smoothing = 0)

RbfMultiscale(X, y, Xnew, supports, degree = -1)

RbfGrid(X, y, xs, ys, ...)

Arguments

r

Distances.

kernel

Kernel name.

epsilon

Shape parameter.

order

Polyharmonic order.

support

Wendland support radius.

X, Xnew

Data and prediction coordinates (matrices).

y

Data values.

degree

Polynomial degree (-1 for none).

smoothing

Smoothing parameter.

transform

Coordinate transform matrix.

epsilons

Candidate shape parameters.

supports

Decreasing Wendland supports.

xs, ys

Grid axes.

...

Options passed to RbfInterpolate.

Value

Numeric or list.

References

Fasshauer, G. E. (2007). Meshfree Approximation Methods with MATLAB. World Scientific.

Rippa, S. (1999). An algorithm for selecting a good value for the parameter c in radial basis function interpolation. Advances in Computational Mathematics 11, 193-210.

Floater, M. S. and Iske, A. (1996). Multistep scattered data interpolation using compactly supported radial basis functions. Journal of Computational and Applied Mathematics 73, 65-78.

Examples

RadialBasis(c(0, 0.5, 1), "wendland")
#> [1] 1.0000 0.1875 0.0000
RbfInterpolate(matrix(0:2), c(0, 1, 0), matrix(0.5), kernel = "cubic")$prediction
#> [1] 0.6875