Extract outer borders between SpatialPolygonsDataFrame units. Outer borders are non-contiguous SpatialPolygonsDataFrame borders (e.g. maritim borders).

getOuterBorders(spdf, spdfid = NULL, res = NULL, width = NULL)

Arguments

spdf
a SpatialPolygonsDataFrame.
spdfid
identifier field in spdf, default to the first column of the spdf data frame. (optional)
res
resolution of the grid used to compute borders (in spdf units). A high resolution will give more detailed borders. (optional)
width
maximum distance between used to compute borders (in spdf units). A higher width will build borders between units that are farther apart. (optional)

Value

A SpatialLinesDataFrame of borders is returned. This object has three id fields: id, id1 and id2. id1 and id2 are ids of units that neighbour a border; id is the concatenation of id1 and id2 (with "_" as separator).

Note

getBorders and getOuterBorders can be combined with rbind.

See also

discLayer, getBorders

Examples

## Not run: ------------------------------------ # data(nuts2006) # # Get units borders # nuts0.outer <- getOuterBorders(nuts0.spdf) # # Plot Countries # plot(nuts0.spdf, border = NA, col = "grey60") # # Plot borders # plot(nuts0.outer, col = sample(x = rainbow(nrow(nuts0.outer))), # lwd = 3, add = TRUE) ## ---------------------------------------------