iknots {bspline} | R Documentation |
Normalized total variation of n-th finite differences is calculated for each column in
y
then averaged. These averaged values are fitted by a linear spline to
find knot positions that equalize the jumps of n-th derivative.
NB. This function is used internally in (fit)smbsp()
and a priori
has no interest to be called directly by user.
iknots(x, y, nki = 1L, n = 3L)
x |
Numeric vector |
y |
Numeric vector or matrix |
nki |
Integer scalar, number of internal knots to estimate (1 by default) |
n |
Integer scalar, polynomial order of B-spline (3 by default) |
Numeric vector, estimated knot positions