antipolygon {GEOmap}R Documentation

Fill the complement of a polygon

Description

Fill a plot with a color outside the confines of a polygon.

Usage

antipolygon(x, y, col = 0, corner=1)

Arguments

x x coordinates of polygon
y y coordinates of polygon
col Fill color
corner Corner on the plot to connect to at the end: 1 = LowerLeft(default) ; 2:UpperLeft 3 = UpperRight; 4=LowerRight

Details

antipolygon uses par("usr") to determine the external bounds of plotting region. Corners are labels from bottom left counter-clockwise, 1-4.

Value

Used for graphical side effect

Note

If the figure is resized after plotting, filling may not appear correct.

Author(s)

Jonathan M. Lees <jonathan.lees@unc.edu>

See Also

polygon, par

Examples

x = runif(100)
y = runif(100)

#########  some data points to plot:

plot(x,y)
###########   create polygon:
pp =list(x=c(0.231,0.316,0.169,0.343,0.311,0.484,0.757,
         0.555,0.800,0.563,0.427,0.412,0.203),
     y=c(0.774,0.622,0.401,0.386,0.138,0.312,0.200,0.459,
        0.658,0.624,0.954,0.686,0.813))

polygon(pp)

antipolygon(x=pp$x, y=pp$y,col='blue')
####  where as this does not look so good
plot(x,y)
antipolygon(x=pp$x, y=pp$y,col='blue', corner=2)



[Package GEOmap version 1.4-0 Index]