This function summarizes both the stepwise selection process of the
model fitting by oldlogspline, as well as the final model
that was selected using AIC/BIC. A
logspline object was fit using
the 1992 knot deletion algorithm (oldlogspline).
The 1997 algorithm using knot
deletion and addition is available using the logspline function.
Usage
## S3 method for class 'oldlogspline'
summary(object, ...)
## S3 method for class 'oldlogspline'
print(x, ...)
Arguments
object,x
oldlogspline object, typically the result of oldlogspline
...
other arguments are ignored.
Details
These function produces the same printed output. The main body
is a table with five columns: the first column is a possible number
of knots for the fitted model;
the second column is the log-likelihood for the fit;
the third column is -2 * loglikelihood + penalty * (number of knots - 1),
which is the AIC criterion; logspline selected the model with
the smallest value of AIC;
the fourth and fifth columns give the
endpoints of the interval of values of penalty that would yield the
model with the indicated number of knots. (NAs imply that the model is
not optimal for any choice of penalty.) At the bottom of the table the
number of knots corresponding to the selected model is reported, as is
the value of penalty that was used.
Charles Kooperberg and Charles J. Stone. Logspline density estimation
for censored data (1992). Journal of Computational and Graphical
Statistics, 1, 301–328.
Charles J. Stone, Mark Hansen, Charles Kooperberg, and Young K. Truong.
The use of polynomial splines and their tensor products in extended
linear modeling (with discussion) (1997). Annals of Statistics,
25, 1371–1470.