perarea function

Compute Perimeters of Objects of Class "SpatialPolygonsDataFrame" and "PolyLinesDataFrame"

calcperimeter computes the perimeters of polygons in objects of class SpatialPolygonsDataFrame and PolyLinesDataFrame.

calcperimeter(x)

Arguments

• x: object of class SpatialPolygonsDataFrame or PolyLinesDataFrame

Returns

an object of class SpatialPolygonsDataFrame or PolyLinesDataFrame with an additionnal column containing the perimeter of the polygons/polylines.

Author(s)

Clement Calenge clement.calenge@ofb.gouv.fr

See Also

SpatialPolygonsDataFrame-class for additionnal information on objects of class SpatialPolygonsDataFrame.

Examples

data(meuse.grid)
a <- SpatialPixelsDataFrame(points = meuse.grid[c("x", "y")],
                            data = meuse.grid)

## the contour of the map
gc <- getcontour(a[,1])
plot(gc)

## Transforms the SpatialPolygons into SpatialPolygonsDataFrame
gc <- SpatialPolygonsDataFrame(gc, data.frame(x=1))

## The perimeter of this map (in units of the data):
ii <- calcperimeter(gc)
as.data.frame(ii)