maptools (version 1.1-8)

SpatialLines2PolySet: Convert sp line and polygon objects to PBSmapping PolySet objects

Description

Functions SpatialLines2PolySet and SpatialPolygons2PolySet convert objects of sp classes to PolySet class objects as defined in the PBSmapping package, and PolySet2SpatialLines and PolySet2SpatialPolygons convert in the opposite direction.

Usage

SpatialLines2PolySet(SL)
SpatialPolygons2PolySet(SpP)
PolySet2SpatialLines(PS)
PolySet2SpatialPolygons(PS, close_polys=TRUE)

Value

PolySet objects as defined in the PBSmapping package

Arguments

SL

a SpatialLines object as defined in the sp package

SpP

a SpatialPolygons object as defined in the sp package

PS

a PolySet object

close_polys

should polygons be closed if open

Author

Roger Bivand and Andrew Niccolai

See Also

PolySet, MapGen2SL

Examples

if(require(PBSmapping) && require(maps)) {
nor_coast_lines <- map("world", interior=FALSE, plot=FALSE, xlim=c(4,32),
 ylim=c(58,72))
nor_coast_lines <- pruneMap(nor_coast_lines, xlim=c(4,32), ylim=c(58,72))
nor_coast_lines_sp <- map2SpatialLines(nor_coast_lines,
 proj4string=CRS("+proj=longlat +datum=WGS84 +ellps=WGS84"))
nor_coast_lines_PS <- SpatialLines2PolySet(nor_coast_lines_sp)
summary(nor_coast_lines_PS)
plotLines(nor_coast_lines_PS)
o3 <- PolySet2SpatialLines(nor_coast_lines_PS)
plot(o3, axes=TRUE)
nor_coast_poly <- map("world", "norway", fill=TRUE, col="transparent",
 plot=FALSE, ylim=c(58,72))
IDs <- sapply(strsplit(nor_coast_poly$names, ":"), function(x) x[1])
nor_coast_poly_sp <- map2SpatialPolygons(nor_coast_poly, IDs=IDs,
 proj4string=CRS("+proj=longlat +datum=WGS84 +ellps=WGS84"))
nor_coast_poly_PS <- SpatialPolygons2PolySet(nor_coast_poly_sp)
summary(nor_coast_poly_PS)
plotPolys(nor_coast_poly_PS)
o1 <- PolySet2SpatialPolygons(nor_coast_poly_PS)
plot(o1, axes=TRUE)
}