elide-methods {maptools}R Documentation

Methods for Function elide in Package 'maptools'

Description

Methods for function elide to translate and disguise coordinate placing in the real world.

Usage

elide(obj, ...)

Arguments

obj object to be elided
... other arguments:
bb
if NULL, uses bounding box of object, otherwise the given bounding box
shift
values to shift the coordinates of the input object; this is made ineffective by the scale argument
reflect
reverse coordinate axes
scale
if NULL, coordinates not scaled; if TRUE, the longer dimension is scaled to lie within [0,1] and aspect maintained; if a scalar, the output range of [0,1] is multiplied by scale
flip
translate coordinates on the main diagonal

Value

The methods return objects of the input class object with elided coordinates; the coordinate reference system is not set. Note that if the input coordinates or centroids are in the data slot data.frame of the input object, they should be removed before the use of these methods, otherwise they will betray the input positions.

Methods

obj = "SpatialPoints"
elides object
obj = "SpatialPointsDataFrame"
elides object
obj = "SpatialLines"
elides object
obj = "SpatialLinesDataFrame"
elides object
obj = "SpatialPolygons"
elides object
obj = "SpatialPolygonsDataFrame"
elides object

Examples

data(meuse)
coordinates(meuse) <- c("x", "y")
proj4string(meuse) <- CRS("+init=epsg:28992")
data(meuse.riv)
river_polygon <- Polygons(list(Polygon(meuse.riv)), ID="meuse")
rivers <- SpatialPolygons(list(river_polygon))
proj4string(rivers) <- CRS("+init=epsg:28992")
rivers1 <- elide(rivers, reflect=c(TRUE, TRUE), scale=TRUE)
meuse1 <- elide(meuse, bb=bbox(rivers), reflect=c(TRUE, TRUE), scale=TRUE)
opar <- par(mfrow=c(1,2))
plot(rivers, axes=TRUE)
plot(meuse, add=TRUE)
plot(rivers1, axes=TRUE)
plot(meuse1, add=TRUE)
par(opar)

[Package maptools version 0.6-19 Index]