locfit (version 19980714-2)

locfit.raw: Local Regression, Likelihood and Density Estimation.

Usage

locfit.raw(x, y, weights, ...)

Arguments

x
Independent variable (or matrix).
y
Response variable.
weights
Prior weights for observations (reciprocal of variance, or sample size).
cens
Censoring indicators for hazard rate or censored regression.
base
Baseline parameter estimate.
xlim
For density estimation, optional vector of lower and upper bounds for variables.
flim
A vector of lower and upper bounds for the evaluation structure. Defaults to the data range.
scale
A scale to apply to each variable. Effectively, the data is transformed before fitting, by dividing each component of the independent variable by the corresponding component of scale.
alpha
Smoothing parameter. A single number (e.g. alpha=0.7) is interpreted as a nearest neighbor fraction. With two componentes (e.g. alpha=c(0.7,1.2)), the first component is a nearest neighbor fraction, and the second component is a
ev
Evaluation Structure, default = "tree". Also available are "phull", "data", "grid", "kdtree", "kdcenter", "crossval".
deg
Degree of local polynomial. Default: 2 (local quadratic).
family
Local likelihood family; "gaussian"; "binomial"; "poisson"; "gamma" and "geom". Density and rate estimation families are "dens", "rate" and "hazard"
link
Link function for local likelihood fitting. Depending on the family, choices may be "ident", "log", "logit", "inverse", "sqrt".
maxk
Controls space assignment for evaluation structures, default 50
kern
Weight function, default = "tcub". Others are "rect", "trwt", "tria", "epan", "bisq" and "gauss". Choices may be restricted when derivatives are required; e.g. for
kt
Kernel type, "sph" (default); "prod". In multivariate problems, \Co{"prod"} uses a simplified product model which speeds up computations.
itype
Integration type for density estimation.
mint
Points for numerical integration rules. Default 20.
maxit
Maximum iterations for local likelihood estimation. Default 20.
cut
Refinement parameter for adaptive partitions. Default 0.8; smaller values result in more refined partitions.
dc
Derivative adjustment.
geth
Don't use!
mg
Margin size for grids.
deriv
Don't use!

Value

  • An object with class "locfit". A standard set of methods for printing, ploting, etc. these objects is provided.

References

Consult the Web page http://cm.bell-labs.com/stat/project/locfit/.