R: Convert sp line and polygon objects to PBSmapping PolySet...

SpatialLines2PolySet {maptools} | R Documentation

## 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)

### 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

### Value

PolySet objects as defined in the PBSmapping package

### Author(s)

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)
    }

[Package maptools version 0.9-3 Index]