TITLE(coplot @@ Conditioning Plots)
USAGE(
coplot(formula, data, given.values, rows, columns,
        show.given=TRUE, col=par("fg"), pch=par("pch"), ...)
co.intervals(x, number=6, overlap=0.5)
)
ALIAS(coplot)
ALIAS(co.intervals)
ARGUMENTS(
ARG(formula @@ a formula describing the form of conditioning
plot.  A formula of the form LANG(y~x|a) indicates that
plots of LANG(y) versus LANG(x) should be produced
conditional on the variable.
A formula of the form LANG(y~x|a*b) indicates that
plots of LANG(y) versus LANG(x) should be produced
conditional on the two variables LANG(a) and LANG(b).
LANG(x) and lang(y) must be numeric, but LANG(a) and LANG(b)
may be either numeric or factors.)
ARG(data @@ a data frame containing values for
any variables in the formula.  By default the
environment where LANG(coplot) was called from is used.)
ARG(given.values @@ a value or list of two values which
determine how the conditioning on LANG(a) and LANG(b)
is to take place. Usually this is a matrix with two columns
which each row of which gives and interval, to be conditioned
on, but is can also be a single vector of numbers
or a set of factor levels (if the variable being conditioned
on is a factor).)
ARG(panel @@ a function which gives the action to be
carried out in each panel of the display.  The default
is LANG(points).)
ARG(rows @@ the panels of the plot are laid out in a
LANG(rows) by LANG(columns) array.
LANG(rows) gives the number of rows in the array.)
ARG(columns @@ the number of columns in the panel layout array.)
ARG(show.given @@ should conditioning plots be shown for the
conditioning variables (default true)).
ARG(col @@ a vector of colors to be ised to plot the points.
If too short, the values are recycled.)
ARG(pch @@ a vector of plotting symbols or characters.
If too short, the values are recycyled.)
ARG(... @@ additional arguments to the panel function.)
ARG(number @@  the number conditioning intervals.)
ARG(overlap @@ the fraction of overlap of the conditioning variables.)
)
DESCRIPTION(
This function produces two variants of the conditioning plots
discussed in the reference.
)
REFERENCES(
Cleveland, W. S. (1993).
ITALIC(Visualizing Data).
New Jersey: Summit Press.
)
SEEALSO(
LANG(LINK(pairs)),
LANG(LINK(panel.smooth)),
LANG(LINK(points)).
)
EXAMPLES(
# Tonga Trench Earthquakes
data(quakes)
coplot(long ~ lat |depth, data=quakes)
coplot(long ~ lat | depth * mag, data=quakes)
)
