ps {DPpackage} | R Documentation |
A symbolic wrapper to indicate a smooth term in a formula argument to PSgam
ps(..., k=50,degree=3,pord=1)
... |
the predictors. |
k |
an integer giving the number of intervals for B-splines. |
degree |
an integer giving the degree of the B-splines. |
pord |
an integer giving the order of difference penalty. |
ps
returns the vectors of predictors, endowed with a number of
attributes. The vector itself is used in the construction of the model
matrix.
Note that ps
does not do the smoothing; it simply sets things up
for PSgam
.
Alejandro Jara <ajarav@udec.cl>
Eilers, P.H.C. and Marx, B.D. (1996) Flexible Smoothing with B-splines and penalties. Statistical Science, 11(2): 89-121.
# fit Start using a smoothing spline with 4 df. y ~ Age + s(Start, degree=4) # fit log(Start) using a smoothing spline with 5 df. y ~ Age + s(log(Start), degree=5)