qtplot.gumbel: Quantile Plot for Gumbel Regression

In VGAM: Vector Generalized Linear and Additive Models

Quantile Plot for Gumbel Regression

Description

Plots quantiles associated with a Gumbel model.

Usage

qtplot.gumbel(object, show.plot = TRUE,
    y.arg = TRUE, spline.fit = FALSE, label = TRUE,
    R = object@misc$R, percentiles = object@misc$percentiles,
    add.arg = FALSE, mpv = object@misc$mpv,
    xlab = NULL, ylab = "", main = "",
    pch = par()$pch, pcol.arg = par()$col,
    llty.arg = par()$lty, lcol.arg = par()$col, llwd.arg = par()$lwd,
    tcol.arg = par()$col, tadj = 1, ...)

Arguments

object	A VGAM extremes model of the Gumbel type, produced by modelling functions such as vglm and vgam, and with a family function that is either gumbel or gumbelff.
show.plot	Logical. Plot it? If FALSE no plot will be done.
y.arg	Logical. Add the raw data on to the plot?
spline.fit	Logical. Use a spline fit through the fitted percentiles? This can be useful if there are large gaps between some values along the covariate.
label	Logical. Label the percentiles?
R	See gumbel.
percentiles	See gumbel.
add.arg	Logical. Add the plot to an existing plot?
mpv	See gumbel.
xlab	Caption for the x-axis. See par.
ylab	Caption for the y-axis. See par.
main	Title of the plot. See title.
pch	Plotting character. See par.
pcol.arg	Color of the points. See the col argument of par.
llty.arg	Line type. Line type. See the lty argument of par.
lcol.arg	Color of the lines. See the col argument of par.
llwd.arg	Line width. See the lwd argument of par.
tcol.arg	Color of the text (if label is TRUE). See the col argument of par.
tadj	Text justification. See the adj argument of par.
...	Arguments passed into the plot function when setting up the entire plot. Useful arguments here include sub and las.

Details

There should be a single covariate such as time. The quantiles specified by percentiles are plotted.

Value

The object with a list called qtplot in the post slot of object. (If show.plot = FALSE then just the list is returned.) The list contains components

fitted.values	The percentiles of the response, possibly including the MPV.
percentiles	The percentiles (small vector of values between 0 and 100.

Note

Unlike gumbel, one cannot have percentiles = NULL.

Author(s)

Thomas W. Yee

See Also

gumbel.

Examples

ymat <- as.matrix(venice[, paste("r", 1:10, sep = "")])
fit1 <- vgam(ymat ~ s(year, df = 3), gumbel(R = 365, mpv = TRUE),
             data = venice, trace = TRUE, na.action = na.pass)
head(fitted(fit1))

## Not run:  par(mfrow = c(1, 1), bty = "l", xpd = TRUE, las = 1)
qtplot(fit1, mpv = TRUE, lcol = c(1, 2, 5), tcol = c(1, 2, 5),
       lwd = 2, pcol = "blue", tadj = 0.4, ylab = "Sea level (cm)")

qtplot(fit1, perc = 97, mpv = FALSE, lcol = 3, tcol = 3,
       lwd = 2, tadj = 0.4, add = TRUE) -> saved
head(saved@post$qtplot$fitted)

## End(Not run)

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