Test Whether Points are Inside a "gpc.poly"
Polygon
inside.gpc.poly.Rd
Same as, e.g., inside.owin
from package spatstat.geom
and point.in.polygon
from package sp,
i.e., test whether points lie inside or outside a given polygon.
Actually, the method for "gpc.poly"
documented here internally uses
the point.in.polygon
function.
Arguments
- x,y
numeric vectors of coordinates of the points to be tested. The coordinates can be supplied in any form accepted by
xy.coords
.- polyregion
an object of class
"gpc.poly"
. It is checked if the points specified throughx
andy
fall into this polygonal region.- mode.checked
passed to
point.in.polygon
.
Details
The nodes and edges of (non-hole) polygons are treated as being inside. Points that fall strictly inside holes are treated as being outside of the polygon.
Value
Logical vector whose i
th entry is TRUE
if the corresponding
point (x[i],y[i])
is inside polyregion
.
Examples
if (surveillance.options("gpclib") && requireNamespace("gpclib")) {
poly <- discpoly(c(0.5,0.5), 0.5, npoly=4, class="gpc.poly")
pts <- cbind(x=runif(50), y=runif(50))
plot(poly)
points(pts, col=1+inside.gpc.poly(pts, polyregion=poly))
}