plot3d.localpoly.reg: 3d plot from a local polynomial fit

In NonpModelCheck: Model Checking and Variable Selection in Nonparametric Regression

Description

Create a 3d plot from a local polynomial fit of two covariates and a response variable.

Usage

plot3d.localpoly.reg(X,Y, bandwidth = "CV", gridsize = 30, 
   degree.pol = 0, kernel.type = "epanech", gridsurface = 30, 
   xlab=expression(X_1), ylab=expression(X_2), 
   zlab=expression(Y), theta = 30, phi = 30, expand = 0.5, 
   col = "lightblue", ltheta = 120, shade = 0.75, 
   ticktype = "detailed", pch = 16,...)

Arguments

X	n by 2 matrix with observations, rows corresponding to data points and columns correspond to covariates.
Y	vector of observed responses.
bandwidth	bandwidth, vector or matrix. If "CV", leave-one-out cross validation with criterion of minimum MSE is performed to select a unique bandwidth that will be used for all dimensions of X; if "GCV", Generalized Cross Validation is performed to select a unique bandwidth that will be used for all dimensions of X; if "CV2" leave-one-out cross validation for each covariate; and if "GCV2", GCV for each covariate. It may be a vector for each dimension of the X; or a matrix of bandwidths (not to be confused with bandwidth matrix H), where each row is a vector of size 2, representing a bandwidth that changes with the location of estimation for the grid. See localpoly.reg.
gridsize	number of possible bandwidths to be searched in cross-validation. If left as default 0, gridsize is taken to be 5+as.integer(100/d^3). If cross-validation is not performed, it is ignored.
degree.pol	degree of the polynomial to be used in the local fit.
kernel.type	kernel type, options are "box", "trun.normal", "gaussian", "epanech", "biweight", "triweight" and "triangular". "trun.normal" is a gaussian kernel truncated between -3 and 3.
gridsurface	number of points on each axis at which to estimate the local polynomial surface.
xlab	parameter for persp
ylab	parameter for persp
zlab	parameter for persp
theta	parameter for persp
phi	parameter for persp
expand	parameter for persp
col	parameter for persp
ltheta	parameter for persp
shade	parameter for persp
ticktype	parameter for persp
pch	parameter for persp
...	further parameters for plotting persp

Details

Uses function "persp" to plot the estimated surface of a local polynomial fit in a nonparametric model with two covariates. The surface is estimated at points of a grid with size "gridsurface", which are evenly distributed between the minimum and maximum of the observed predictors. It also adds the observed points to the plot.

Value

X	the same input matrix
Y	the same input response vector
points	points at which to get smoothed values
bandwidth	bandwidth used for the polynomial fit
predicted	matrix with the predicted values at grid points

Author(s)

Adriano Zanin Zambom <[e-mail]>

See Also

localpoly.reg

Examples

X = matrix(0,50,2)
X[,1] = runif(50,-2,2)
X[,2] = runif(50,-2,2)
Y = 4*sin(pi*X[,1]) + X[,2] + rnorm(50)

plot3d.localpoly.reg(X,Y, bandwidth= c(0.44, 1.84), gridsize = 15, 
degree.pol = 0, gridsurface=20)	

NonpModelCheck documentation built on Sept. 8, 2021, 5:08 p.m.