plot.owin
Plot a Spatial Window
Plot a two-dimensional window of observation for a spatial point pattern
Usage
## S3 method for class 'owin':
plot(x, main, add=FALSE, \dots, box, edge=0.04,
hatch=FALSE, angle=45, spacing=diameter(x)/50,
invert=FALSE)
Arguments
- x
- The window to be plotted.
An object of class
owin
, or data which can be converted into this format byas.owin()
. - main
- text to be displayed as a title above the plot.
- add
- logical flag: if
TRUE
, draw the window in the current plot; ifFALSE
, generate a new plot. - ...
- extra arguments passed to the generic
plot
function. - box
- logical flag; if
TRUE
, plot the enclosing rectangular box - edge
- nonnegative number; the plotting region will have coordinate limits
that are
1 + edge
times as large as the limits of the rectangular box that encloses the pattern. - hatch
- logical flag; if
TRUE
, the interior of the window will be shaded by a grid of parallel lines. - angle
- orientation of the shading lines (in degrees anticlockwise
from the $x$ axis) when
hatch=TRUE
. - spacing
- spacing between the shading lines,
when
hatch=TRUE
. - invert
- logical flag; when the window is a binary pixel mask,
the mask colours will be inverted if
invert=TRUE
.
Details
This is the plot
method for the class owin
.
The action is to plot the boundary of the window on the current plot device,
using equal scales on the x
and y
axes.
If the window x
is of type "rectangle"
or "polygonal"
,
the boundary of the window is plotted as a polygon or series of polygons.
If x
is of type "mask"
the discrete raster approximation of the window is displayed
as a binary image (white inside the window, black outside).
Graphical parameters controlling the display (e.g. setting the
colours) may be passed directly via the ...
arguments,
or indirectly reset using
spatstat.options
.
When x
is of type "rectangle"
or "polygonal"
, it
is plotted by the Rfunction polygon
. To control the
appearance (colour, fill density, line density etc) of the polygon
plot, determine the required argument of polygon
and
pass it through ...
For example, to paint the interior of the
polygon in red, use the argument col="red"
. To draw the polygon
edges in green, use border="green"
. To suppress the drawing of
polygon edges, use border=NA
.
When x
is of type "mask"
, it is plotted by
image.default
. The appearance of the image plot
can be controlled by passing arguments to image.default
through ...
. The default appearance can also be changed
by setting the parameter par.binary
of
spatstat.options
.
To zoom in (to view only a subset of the window at higher
magnification), use the graphical arguments
xlim
and ylim
to specify the desired rectangular field of
view. (The actual field of view may be larger, depending on the
graphics device).
Value
- none.
Cairo graphics on a Linux system
Linux systems support
the graphics device X11(type="cairo")
(see X11
)
provided the external library capabilities()["cairo"]
.
The default type for X11
is controlled by
X11.options
.
You may find it convenient to
make .Rprofile
.
The magic incantation to put into .Rprofile
is
setHook(packageEvent("graphics", "onLoad"),
function(...) grDevices::X11.options(type="cairo"))
See Also
owin.object
,
plot.ppp
,
polygon
,
image.default
,
spatstat.options
Examples
# rectangular window
data(nztrees)
plot(nztrees$window)
abline(v=148, lty=2)
# polygonal window
data(demopat)
w <- demopat$window
plot(w)
plot(w, col="red", border="green", lwd=2)
plot(w, hatch=TRUE, lwd=2)
# binary mask
we <- as.mask(erosion(w, 400, FALSE))
plot(we)
spatstat.options(par.binary=list(col=grey(c(0.5,1))))
plot(we)