DerivIntSplines function

Derivatives and Integrals of B-splines and Natural Cubic splines

Numerical derivatives and integrals of functions bs() and ns() at their first argument.

dns(x, df = NULL, knots = NULL, intercept = FALSE, 
    Boundary.knots = range(x), eps = 1e-03)

dbs(x, df = NULL, knots = NULL, intercept = FALSE, 
    Boundary.knots = range(x), eps = 1e-03)

ins(x, df = NULL, knots = NULL, intercept = FALSE, 
    Boundary.knots = range(x), from = 0, weight.fun = NULL, 
    integrand.fun = NULL, ...)

ibs(x, df = NULL, knots = NULL, intercept = FALSE, 
    Boundary.knots = range(x), from = 0, weight.fun = NULL, 
    integrand.fun = NULL, ...)

Arguments

• x, df, knots, intercept, Boundary.knots: see the help pages of functions ns() and bs().
• eps: a numeric scalar denoting the step length for the central difference approximation, which calculates the derivative.
• from: a numeric scalar denoting the lower limit of the integral.
• weight.fun: a function to be applied as weights.
• integrand.fun: a function to be applied in the integrand.
• ...: extra arguments passed to weight.fun.

Returns

an object of class dns, dbs, ins or ibs.

Author(s)

Dimitris Rizopoulos d.rizopoulos@erasmusmc.nl