VGAM (version 0.7-10)

plotdeplot.lmscreg: Density Plot for LMS Quantile Regression

Description

Plots a probability density function associated with a LMS quantile regression.

Usage

plotdeplot.lmscreg(answer, y.arg, add.arg = FALSE, 
    xlab = "", ylab = "density", xlim = NULL, ylim = NULL, 
    llty.arg = par()$lty, col.arg = par()$col, 
    llwd.arg = par()$lwd, ...)

Value

• The list answer, which has components
• newdata
  The argument newdata above from the argument list of deplot.lmscreg, or a one-row data frame constructed out of the x0 argument.
• y
  The argument y.arg above.
• density
  Vector of the density function values evaluated at y.arg.

Details

The above graphical parameters offer some flexibility when plotting the quantiles.

References

Yee, T. W. (2004) Quantile regression via vector generalized additive models. Statistics in Medicine, 23, 2295--2315.

Documentation accompanying the VGAM package at http://www.stat.auckland.ac.nz/~yee contains further information and examples.

See Also

deplot.lmscreg.

Examples

fit = vgam(BMI ~ s(age, df=c(4,2)), fam=lms.bcn(zero=1), data=bminz)
y = seq(15, 43, by=0.25)
deplot(fit, x0=20, y=y, xlab="BMI", col="green", llwd=2,
       main="BMI distribution at ages 20 (green), 40 (blue), 60 (red)")
deplot(fit, x0=40, y=y, add=TRUE, col="blue", llwd=2)
deplot(fit, x0=60, y=y, add=TRUE, col="red", llwd=2) -> a

names(a@post$deplot)
a@post$deplot$newdata
head(a@post$deplot$y)
head(a@post$deplot$density)