Polygonal Basis Function Values
polyg |
Language Reference for FDA Library
|
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.
- 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.
OPTIONAL ARGUMENTS:
- nderiv
-
the order of 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
SEE ALSO:
create.polygonal.basis, polygpen
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")