Useful panel function with qqmath. Draws a line passing through the points (usually) determined by the .25 and .75 quantiles of the sample and the theoretical distribution.
panel.qqmathline(x, y = x,
distribution = qnorm,
probs = c(0.25, 0.75),
qtype = 7,
groups = NULL,
…,
identifier = "qqmathline")The original sample, possibly reduced to a fewer number of
quantiles, as determined by the f.value argument to
qqmath
an alias for x for backwards compatibility
quantile function for reference theoretical distribution.
numeric vector of length two, representing probabilities. Corresponding quantile pairs define the line drawn.
the type of quantile computation used in
quantile
optional grouping variable. If non-null, a line will be drawn for each group.
other arguments.
A character string that is prepended to the names of grobs that are created by this panel function.