Plot a Variogram Cloud
DESCRIPTION:
Display variogram cloud object.
USAGE: 
plot.vgram.cloud(x, ...)
REQUIRED ARGUMENTS:
x:
an object of class "vgram.cloud".

Graphical parameters may also be supplied as arguments to this function (see par).

SIDE EFFECTS:
a plot is produced on the current graphics device.
DETAILS:
This function is a method for the generic function plot for class "vgram.cloud". It can be invoked by calling plot for an object of the appropriate class, or directly by calling plot.vgram.cloud regardless of the class of the object.
SEE ALSO:
variogram.cloud , plot .
EXAMPLES: 
v1 <- variogram.cloud(coal ~ x + y, data=coal.ash)
plot(v1)