ispline: Quadratic monotone spline basis function for given knots.
Description
Calculate basis functions for monotone quadratic splines.
Usage
ispline(xvec, tvec = c(0, 0.5, 1), intercept = TRUE)
Arguments
- xvec
Vector at which to evaluate the basis functions.
- tvec
Vector of spline knots: lower endpoint, interior knot, upper endpoint.
- intercept
Logical; should an intercept be included or not?