SpatialLines2PolySet        package:maptools        R Documentation

_C_o_n_v_e_r_t _s_p _l_i_n_e _a_n_d _p_o_l_y_g_o_n _o_b_j_e_c_t_s _t_o _P_B_S_m_a_p_p_i_n_g _P_o_l_y_S_e_t _o_b_j_e_c_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     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.

_U_s_a_g_e:

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

_A_r_g_u_m_e_n_t_s:

      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

_V_a_l_u_e:

     PolySet objects as defined in the PBSmapping package

_A_u_t_h_o_r(_s):

     Roger Bivand and Andrew Niccolai

_S_e_e _A_l_s_o:

     'as.PolySet', 'MapGen2SL'

_E_x_a_m_p_l_e_s:

     library(PBSmapping)
     library(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"))
     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"))
     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)

