dilated.areas(X, r, W=as.owin(X), ..., constrained=TRUE, exact = FALSE)
"ppp"
),
a line segment pattern (object of class "psp"
),
or a window (object of class "owin"
)."owin"
) inside which the areas
will be computed, if constrained=TRUE
.W
.X
is a point pattern.X
by each of the radii r[i]
. Areas may also be computed
inside a specified window W
.The morphological dilation of a set $X$ by a distance $r > 0$ is the subset consisting of all points $x$ such that the distance from $x$ to $X$ is less than or equal to $r$.
When X
is a point pattern, the dilation by a distance
$r$ is the union of
discs of radius $r$ centred at the points of X
.
The argument r
should be a vector of nonnegative numbers.
If exact=TRUE
and if X
is a point pattern,
then the areas are computed using analytic geometry, which is
slower but much more accurate. Otherwise the computation is performed
using distmap
.
To compute the dilated object itself, use dilation
.
owin
,
as.owin
,
dilation
,
eroded.areas
X <- runifpoint(10)
a <- dilated.areas(X, c(0.1,0.2), W=square(1), exact=TRUE)
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