textstring(x, y, txt = NULL, ...)
onearrow(x0, y0, x1, y1, txt = NULL, ...)
yardstick(x0, y0, x1, y1, txt = NULL, ...)
x0
can be a point pattern (class "ppp"
)
containing exactly two points, or a line segment pattern
(class "psp"
) consisting of exactly one line segment.
"diagramobj"
which also
belongs to one of the special classes "textstring"
, "onearrow"
or "yardstick"
. There are methods for plot
,
print
, "["
and shift
.
textstring
creates an object that represents a string
of text at a particular spatial location.
onearrow
creates an object that represents an arrow
between two locations.
yardstick
creates an object that represents
a scale bar: a line segment indicating the scale of the plot.
To display the relevant object, it should be plotted, using
plot
. See the help files for the plot methods
plot.textstring
, plot.onearrow
and plot.yardstick
.
These objects are designed to be included as components in a
layered
object or a solist
. This makes it
possible to build up a diagram consisting of many spatial objects,
and to annotate the diagram with arrows, text and so on, so that
ultimately the entire diagram is plotted using plot
.
plot.textstring
,
plot.onearrow
,
plot.yardstick
.
X <- rescale(swedishpines)
plot(X, pch=16, main="")
ys <- yardstick(as.psp(list(xmid=4, ymid=0.5, length=1, angle=0),
window=Window(X)),
txt="1 m")
plot(ys, angle=90)
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