F_1_panel.qqmath: Default Panel Function for qqmath

Description

This is the default panel function for qqmath.

Usage

panel.qqmath(x, f.value = NULL,
             distribution = qnorm,
             qtype = 7,
             groups = NULL, ...,
             tails.n = 0,
             identifier = "qqmath")

Arguments

x: vector (typically numeric, coerced if not) of data values to be used in the panel.
f.value, distribution: Defines how quantiles are calculated. See qqmath for details.
qtype: The type argument to be used in quantile
groups: An optional grouping variable. Within each panel, one Q-Q plot is produced for every level of this grouping variable, differentiated by different graphical parameters.
...: Further arguments, often graphical parameters, eventually passed on to panel.xyplot. Arguments grid and abline of panel.xyplot may be particularly useful.
tails.n: number of data points to represent exactly on each tail of the distribution. This reproduces the effect of f.value = NULL for the extreme data values, while approximating the remaining data. It has no effect if f.value = NULL. If tails.n is given, qtype is forced to be 1.
identifier: A character string that is prepended to the names of grobs that are created by this panel function.

Author

Deepayan Sarkar Deepayan.Sarkar@R-project.org

Details

Creates a Q-Q plot of the data and the theoretical distribution given by distribution. Note that most of the arguments controlling the display can be supplied directly to the high-level qqmath call.

Examples

Run this code

set.seed(0)
xx <- rt(10000, df = 10)
qqmath(~ xx, pch = "+", distribution = qnorm,
       grid = TRUE, abline = c(0, 1),
       xlab.top = c("raw", "ppoints(100)", "tails.n = 50"),
       panel = function(..., f.value) {
           switch(panel.number(),
                  panel.qqmath(..., f.value = NULL),
                  panel.qqmath(..., f.value = ppoints(100)),
                  panel.qqmath(..., f.value = ppoints(100), tails.n = 50))
       }, layout = c(3, 1))[c(1,1,1)]