preplot.locfit {locfit}  R Documentation 
Prediction from a Locfit object.
Description
preplot.locfit
can be called directly, although it is more usual
to call plot.locfit
or predict.locfit
.
The advantage of preplot.locfit
is in SPlus 5, where arithmetic
and transformations can be performed on the "preplot.locfit"
object.
plot(preplot(fit))
is essentially synonymous with plot(fit)
.
Usage
## S3 method for class 'locfit'
preplot(object, newdata=NULL, where, tr=NULL, what="coef",
band="none", get.data=FALSE, f3d=FALSE, ...)
Arguments
object 
Fitted object from locfit() .

newdata 
Points to predict at. Can be given in several forms:
vector/matrix; list, data frame.

where 
An alternative to newdata . Choices include
"grid" for the grid lfmarg(object) ;
"data" for the original data points and "fitp" for the
direct fitting points (ie. no interpolation).

tr 
Transformation for likelihood models. Default is the inverse
of the link function.

what 
What to compute predicted values of. The default,
what="coef" , works with the fitted curve itself. Other
choices include "nlx" for the length of the weight diagram;
"infl" for the influence function; "band" for the
bandwidth; "degr" for the local polynomial degree;
"lik" for the maximized local likelihood; "rdf" for
the local residual degrees of freedom and "vari" for the
variance function. The interpolation algorithm for some of these
quantities is questionable.

band 
Compute standard errors for the fit and include confidence
bands on the returned object. Default is "none" . Other
choices include "global" for bands using a global variance
estimate; "local" for bands using a local variance estimate
and "pred" for prediction bands (at present, using a global
variance estimate). To obtain the global variance estimate for a
fit, use rv . This can be changed with
rv< . Confidence bands, by default, are 95%, based on
normal approximations and neglecting bias. To change the critical
value or confidence level, or to obtain simultaneous instead of
pointwise confidence, the critical value stored on the fit must be
changed. See the kappa0 and crit
functions.

get.data 
If TRUE , the original data is attached to the
returned object, and added to the plot.

f3d 
If TRUE , sets a flag that forces ploting using the
trellis style. Not available in R.

... 
arguments passed to and from other methods.

Value
An object with class "preplot.locfit"
, containing the predicted
values and additional information used to construct the plot.
See Also
locfit
, predict.locfit
, plot.locfit
.
[Package
locfit version 1.59.10
Index]