plotdeplot.lmscreg: Density Plot for LMS Quantile Regression

In VGAM: Vector Generalized Linear and Additive Models

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, ...)

Arguments

answer	Output from functions of the form deplot.??? where ??? is the name of the VGAM LMS family function, e.g., lms.yjn. See below for details.
y.arg	Numerical vector. The values of the response variable at which to evaluate the density. This should be a grid that is fine enough to ensure the plotted curves are smooth.
add.arg	Logical. Add the density to an existing plot?
xlab, ylab	Caption for the x- and y-axes. See par.
xlim, ylim	Limits of the x- and y-axes. See par.
llty.arg	Line type. See the lty argument of par.
col.arg	Line color. See the col argument of par.
llwd.arg	Line width. See the lwd argument of par.
...	Arguments passed into the plot function when setting up the entire plot. Useful arguments here include main and las.

Details

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

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.

Note

While the graphical arguments of this function are useful to the user, this function should not be called directly.

Author(s)

Thomas W. Yee

References

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

See Also

deplot.lmscreg.

Examples

fit <- vgam(BMI ~ s(age, df = c(4,2)), lms.bcn(zero = 1), bmi.nz)
## Not run:  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 (orange)")
deplot(fit, x0 = 40, y = y, add = TRUE, col = "blue", llwd = 2)
deplot(fit, x0 = 60, y = y, add = TRUE, col = "orange", llwd = 2) -> aa

names(aa@post$deplot)
aa@post$deplot$newdata
head(aa@post$deplot$y)
head(aa@post$deplot$density) 
## End(Not run)

VGAM documentation built on Sept. 18, 2024, 9:09 a.m.