THINPLATE procedure

Calculates the basis functions for thin-plate splines (S.J. Welham & D.B. Baird).

No options

Parameters

Y = variates or factors

Y-coordinates of the data points

X = variates or factors

X-coordinates of the data points

YKNOTS = variates or factors

Y-coordinates of the knots

XKNOTS = variates or factors

X-coordinates of the knots

TPSPLINE = variates or matrices

Thin-plate spline basis, as either a pointer of variates (default if not already declared) or a matrix

Description

THINPLATE calculates the basis functions for thin-plate splines. The X and Y parameters each specify a variate or a factor with the x- and y-coordinates of the data points, and the XKNOTS and YKNOTS parameters similarly specify the positions of the knots. The basis functions are saved by the TPSPLINE parameter. By default these are stored in a pointer of variates, but you can save a matrix instead by declaring TPSPLINE in advance to be a matrix.

Options: none.

Parameters: Y, X, YKNOTS, XKNOTS, TPSPLINE.