Exponential Basis Function Values

Exponential Basis Function Values

DESCRIPTION:

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

USAGE:

expon(x, ratevec=1, nderiv=0)

REQUIRED ARGUMENTS:

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

OPTIONAL ARGUMENTS:

ratevec
A vector of rate values defining the exponential basis functions. If b is such a rate value, the corresponding basis function is ebx. The number of basis functions is equal to the number of rate constants. The default is the single constant one.
nderiv
The derivative to be evaluated. The derivative must not exceed the order. 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 11 argument values
x <- seq(0,1,0.1)
#  compute values for three exponential basis functions
ratevec <- c(-1, 0, 1)
#  compute the basis function values
basismat <- expon(x, ratevec)