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 `border`

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`

.

The user can set the default values of these plotting parameters
using `spatstat.options("par.points")`

.
To zoom in (to view only a subset of the point pattern at higher
magnification), use the graphical arguments
`xlim`

and `ylim`

to specify the rectangular field of view.

The value returned by this plot function can be used to make a
suitable legend, as shown in the examples.