Polygonal Basis Function Values

Polygonal Basis Function Values

DESCRIPTION:

Evaluates a set of polygonal basis functions, or a derivative of these functions, at a set of arguments.

USAGE:

polyg(x, argvals, nderiv=0)

REQUIRED ARGUMENTS:

x
A vector of argument values at which the polygonal basis functions are to evaluated.

OPTIONAL ARGUMENTS:

argvals
A strictly increasing set of argument values containing the range of x within it that defines the polygonal basis. The default is x itself.
nderiv
The derivative to be evaluated. The derivative must not exceed one. The default derivative is 0, meaning that the basis functions themselves are evaluated.

VALUE:

A matrix of function values. The number of rows equals the number of arguments, and the number of columns equals the number of basis

EXAMPLES:

#  set up a set of 21 argument values
x <- seq(0,1,0.05)
#  set up a set of 11 argument values
argvals <- seq(0,1,0.1)
#  with the default period (1) and derivative (0)
basismat <- polyg(x, argvals)
#  plot the basis functions
matplot(x, basismat, type="l")