Takes two vectors or a list with
x and
y components, and produces
back to back histograms of the two datasets.
USAGE:
histbackback(x, y, brks=NULL, xlab=NULL, axes=TRUE, probability=FALSE,
xlim=NULL, ylab='', ...)
ARGUMENTS:
x,y
either two vectors or a list given as
x with two components. If the
components have names, they will be used to label the axis
(modification FEH).
brks
vector of the desired breakpoints for the histograms.
xlab
a vector of two character strings naming the two datasets.
axes
logical flag stating whether or not to label the axes.
probability
logical flag: if
TRUE, then the x-axis corresponds to the units for a
density. If
FALSE, then the units are counts.
xlim
x-axis limits. First value must be negative, as the left histogram is
placed at negative x-values. Second value must be positive, for the
right histogram. To make the limits symmetric, use e.g.
ylim=c(-20,20).
ylab
label for y-axis. Default is no label.
...
additional graphics parameters may be given.
VALUE:
a list is returned invisibly with the following components:
left
the counts for the dataset plotted on the left.
right
the counts for the dataset plotted on the right.
breaks
the breakpoints used.
AUTHOR(S):
Pat Burns
Salomon Smith Barney
London
pburns@dorado.sbi.com