GEOmap (version 2.5-2)

antipolygon: 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, pct=.4)

Value

List:

x

x-coordinates of mask

y

y-coordinates of mask

Used for graphical side effect

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

pct

Decimal percent of usr coordinates to expand beyond the polygon

Author

Jonathan M. Lees <[e-mail]>

Details

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

See Also

polygon, par

Examples

set.seed(2018)
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)