Adds a legend to the plot of an object of class
hexbin. To be called
by the corresponding
plot method. The legend represents
the lattice counts. This function is support for
plot.hexbin, it is
not meant to be called directly by the user.
numeric vector of color numbers used to color the different levels in the
color legend.
at
numeric vector specifying the values at which the colors change.
OPTIONAL ARGUMENTS:
labels
a character vector of tick labels marking the value of
at.
legend.lab
a character string denoting a title for the legend itself. The default
is "Counts".
height
total height of the legend in inches. The default is 3 inches.
lcex
numeric constant. Character expansion for the legend text. Default is 1.
width
numeric constant giving the desired width of the legend. Default is 1.
inner
numeric constant needed to determine the size of the hexagons. Default
is computed as a function of
width. (Inner diameter in inches.)
style
character string. One of 5 possible styles for plotting the hexagons.
This must be one of
"grayscale",
"lattice",
"centroids",
"nested.lattice", or
"nested.centroids".
minarea
fraction of cell area for the lowest count. Default is 0.04 or 4%.
maxarea
fraction of the cell area for the largest count. Default is 80%.
maxcount
cells with more counts than
maxcount are ignored.
density
same as the corresponding argument in the function
polygon. If
density
is zero, no shading will occur. If
density is negative, the hexagons
will be filled solidly.
SIDE EFFECTS:
A legend is added to the current plot.
DETAILS:
This function must not be used as a standalone function. It is meant to be
called from
plot.hexbin.