bgrid: Create a bi-orthogonal grid

In EnviroStat: Statistical Analysis of Environmental Space-Time Processes

Description

Function to create a biorthogonal grid using the thin-plate solution; the grid object created can be used with the draw function to plot the grid.

Usage

bgrid(start, xmat, coef, xlimt, iter.limit = 10, perpc = 8)

Arguments

start	coordinates of the starting point to create the grid - usually near the center of region
xmat	n x 2 matrix containing xy coordinates of locations
coef	coefficients of the thin-plate solution, for instance as returned by sinterp
xlimt	vector of 4 elements, representing x- and y-ranges for the grid to be created; if not provided, the ranges of xmat are used.
iter.limit	limit of iterations
perpc	parameter to control spacing of the grid

Value

A list with following named components:

grid	coordinates of points in the grid
ngrid	number of points in the grid
fldmag	the “gradient” index (see Sampson and Guttorp, 1992, for details)
nn	internally set for the maximum number of grid points allowed

References

Sampson P.D., and Guttorp, P., "Nonparametric estimation of nonstationary spatial covariance structure", in Journal of the American Statistical Association, vol 87, pp 108-119, 1992.

See Also

draw, sinterp

EnviroStat documentation built on May 2, 2019, 2:32 p.m.