| SpatialLines2PolySet {maptools} | R Documentation |
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.
SpatialLines2PolySet(SL) SpatialPolygons2PolySet(SpP) PolySet2SpatialLines(PS) PolySet2SpatialPolygons(PS, close_polys=TRUE)
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 |
PolySet objects as defined in the PBSmapping package
Roger Bivand and Andrew Niccolai
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)
}