new-generics {gpclib}R Documentation

Generics/Methods for polygon objects

Description

Some generic functions and methods for polygon objects

Usage

append.poly(x, y)
area.poly(object, ...)
get.pts(object)
get.bbox(x)
scale.poly(x, ...)

Arguments

x,object A polygon object
y A polygon object
... Other arguments passed to methods

Details

Methods

append.poly
signature(x = "gpc.poly", y = "gpc.poly"): Combine all contours of two "gpc.poly" objects and return the combined polygon as a "gpc.poly" object.
area.poly
signature(object = "gpc.poly"): Compute and return the sum of the areas of all contours in a "gpc.poly" object.
scale.poly
signature(x = "gpc.poly"): Scale (divide) the x and y coordinates of a "gpc.poly" object by the amount xscale and yscale, respectively. Return a scaled "gpc.poly" object.
get.pts
signature(object = "gpc.poly"): Return the list of x and y coordinates of the vertices of a "gpc.poly" object.
get.bbox
signature(x = "gpc.poly"): Return the bounding box for a "gpc.poly" object.

Author(s)

Roger D. Peng; GPC Library by Alan Murta

See Also

"gpc.poly" class documentation.

Examples

holepoly <- read.polyfile(system.file("poly-ex/hole-poly.txt", package =
"gpclib"), nohole = FALSE)
area.poly(holepoly)
stopifnot(area.poly(holepoly) == 8)

[Package gpclib version 1.3 Index]