periodic {assist} | R Documentation |
Return a matrix evaluating reproducing kernels for periodic polynomial splines at observed points.
periodic(s, t=s, order=2)
s |
a numeric vector. |
t |
an optional vector. Default is the same as s. |
order |
an optional integer sepcifying the order of the polynomial spline. Default is 2 for the periodic cubic spline. |
The general formula of the reproducing kernel is sum of an infinite series, which is approximated by taking the first 50 terms. For the case of order=2, the close form is available and used.
a matrix with the numbers of row and column equal to the lengths of s and t respectively. The [i, j] element is the reproducing kernel evaluated at (s[i], t[j]).
Wahba, G. (1990). Spline Models for Observational Data. SIAM, Vol. 59.
Gu, C. (2001). Smoothing Spline ANOVA Modes. Chapman and Hall.
## Not run: x<- seq(0, 1, len=100) periodic(x, order=3) ## End(Not run)