sp (version 0.7-6)

shp2SLDF: Converter functions to build SpatialLinesDataFrame objects

Description

These functions show how to build converters from external formats to build SpatialLinesDataFrame objects: shp2SLDF from "arc" type ESRI shapefiles read into "Map" objects using the read.shape() function in the maptools package; arcobj2SLDF from the list returned by the get.arcdata function in the RArcInfo package; and contourLines2SLDF from the list returned by the contourLines function in the graphics package (here the data frame is just the contour levels, with one Slines object made up of at least one Sline object per level).

Usage

shp2SLDF(shp, proj4string = CRS(as.character(NA)))
arcobj2SLDF(arc, proj4string=CRS(as.character(NA)))
contourLines2SLDF(cL, proj4string=CRS(as.character(NA)))

Arguments

shp

a "Map" object returned by the read.shape() function in the maptools package

arc

a list returned by the get.arcdata function in the RArcInfo package

cL

a list returned by the contourLines function in the graphics package

proj4string

Object of class "CRS"; see CRS-class

Value

• A SpatialLinesDataFrame object

See Also

SpatialLines-class

Examples

data(lnsshp) # retrieved as: 
# library(maptools)
# lns <- read.shape(system.file("shapes/fylk-val.shp", package="maptools")[1])
res <- shp2SLDF(lns)
plot(res)
invisible(title(""))
data(co37_d90_arc) # retrieved as: 
# library(RArcInfo)
# fl <- "http://www.census.gov/geo/cob/bdy/co/co90e00/co37_d90_e00.zip"
# download.file(fl, "co37_d90_e00.zip")
# e00 <- zip.file.extract("co37_d90.e00", "co37_d90_e00.zip")
# e00toavc(e00, "ncar")
# arc <- get.arcdata(".", "ncar")
res <- arcobj2SLDF(arc)
plot(res)
invisible(title(""))
res <- contourLines2SLDF(contourLines(volcano))
plot(res, col=terrain.colors(nrow(res@data)))
invisible(title(""))