This is the plot method for
point pattern datasets (of class "ppp", see ppp.object). First the observation window x$window is plotted.
Then the points themselves are plotted,
in a fashion that depends on their marks,
as follows.
[object Object],[object Object],[object Object],[object Object]
Plotting of the window x$window is performed by
plot.owin. This plot may be modified
through the ... arguments. In particular the
extra argument col determines the colour of the window.
Plotting of the points themselves is performed
by the function points, except for the case of
continuous marks, where it is performed by symbols.
Their plotting behaviour may be modified through the ...
arguments.
The argument chars determines the plotting character
or characters used to display the points (in all cases except
for the case of continuous marks). For an unmarked point pattern,
this should be a single integer or character determining a
plotting character (see par("pch")).
For a multitype point pattern, chars should be a vector
of integers or characters, of the same length
as levels(x$marks), and then the $i$th level or type
will be plotted using character chars[i].
If chars is absent, but there is an extra argument
pch, then this will determine the plotting character for
all points.
The argument cols determines the colour or colours used to
display the points. For an unmarked point pattern, or a
marked point pattern with continuous marks, this should be a character string
determining a colour. For a multitype point pattern, cols
should be a character vector, of the same length
as levels(x$marks). The $i$th level or type will
be plotted using colour cols[i].
If cols is absent, the colour used to plot all the
points may be determined by the extra argument fg
(for multitype point patterns) or the extra argument col
(for all other cases). Note that col will also reset the
colour of the window.
The arguments maxsize and markscale
incompatible. They control the physical size of the circles and
squares which represent the marks in a point pattern with continuous
marks. If markscale is given, then a mark value of m
is plotted as a circle of radius m * markscale
(if m is positive) or a square of side abs(m) * markscale
(if m is negative). If maxsize is given, then the
largest mark in absolute value, mmax=max(abs(x$marks)),
will be scaled to have physical size maxsize.