svysmooth: Scatterplot smoothing and density estimation

Description

Scatterplot smoothing and density estimation for probability-weighted data.

Usage

svysmooth(formula, design, ...)
# S3 method for default
svysmooth(formula, design, method = c("locpoly", "quantreg"), 
    bandwidth = NULL, quantile, df = 4, ...)
# S3 method for svysmooth
plot(x, which=NULL, type="l", xlabs=NULL, ylab=NULL,...)
# S3 method for svysmooth
lines(x,which=NULL,...)
make.panel.svysmooth(design,bandwidth=NULL)

Value

An object of class svysmooth, a list of lists, each with x and y components.

Arguments

formula: One-sided formula for density estimation, two-sided for smoothing
design: Survey design object
method: local polynomial smoothing for the mean or regression splines for quantiles
bandwidth: Smoothing bandwidth for "locpoly" or NULL for automatic choice
quantile: quantile to be estimated for "quantreg"
df: Degrees of freedom for "quantreg"
which: Which plots to show (default is all)
type: as for plot
xlabs: Optional vector of x-axis labels
ylab: Optional y-axis label
...: More arguments
x: Object of class svysmooth

Details

svysmooth does one-dimensional smoothing. If formula has multiple predictor variables a separate one-dimensional smooth is performed for each one.

For method="locpoly" the extra arguments are passed to locpoly from the KernSmooth package, for method="quantreg" they are passed to rq from the quantreg package. The automatic choice of bandwidth for method="locpoly" uses the default settings for dpik and dpill in the KernSmooth package.

make.panel.svysmooth() makes a function that plots points and draws a weighted smooth curve through them, a weighted replacement for panel.smooth that can be passed to functions such as termplot or plot.lm. The resulting function has a span argument that will set the bandwidth; if this is not specified the automatic choice will be used.

Examples

Run this code

 data(api)
 dstrat<-svydesign(id=~1,strata=~stype, weights=~pw, data=apistrat, fpc=~fpc)

 smth<-svysmooth(api00~api99+ell,dstrat)
 dens<-svysmooth(~api99, dstrat,bandwidth=30)
 dens1<-svysmooth(~api99, dstrat)
 qsmth<-svysmooth(api00~ell,dstrat, quantile=0.75, df=3,method="quantreg")

 plot(smth)
 plot(smth, which="ell",lty=2,ylim=c(500,900))
 lines(qsmth, col="red")

 svyhist(~api99,design=dstrat)
 lines(dens,col="purple",lwd=3)
 lines(dens1, col="forestgreen",lwd=2)

 m<-svyglm(api00~sin(api99/100)+stype, design=dstrat)
 termplot(m, data=model.frame(dstrat), partial.resid=TRUE, se=TRUE,
  smooth=make.panel.svysmooth(dstrat))