ContourLines2SLDF: Converter functions to build SpatialLinesDataFrame objects

Description

These functions show how to build converters to SpatialLinesDataFrame objects: ArcObj2SLDF from the list returned by the get.arcdata function in the RArcInfo package; ContourLines2SLDF from the list returned by the contourLines function in the graphics package (here the data frame is just the contour levels, with one Lines object made up of at least one Line object per level); and MapGen2SL reads a file in "Mapgen" format into a SpatialLines object.

Usage

ArcObj2SLDF(arc, proj4string=CRS(as.character(NA)), IDs)
ContourLines2SLDF(cL, proj4string=CRS(as.character(NA)))
MapGen2SL(file, proj4string=CRS(as.character(NA)))

Value

A SpatialLinesDataFrame object

Arguments

arc: a list returned by the get.arcdata function in the RArcInfo package
IDs: vector of unique character identifiers; if not given, suitable defaults will be used, and the same values inserted as data slot row names
cL: a list returned by the contourLines function in the graphics package
proj4string: Object of class "CRS"; see CRS-class
file: filename of a file containing a Mapgen line data set

Author

Roger Bivand; Edzer Pebesma

Examples

Run this code

#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(as(res, "data.frame"))))
title("Volcano contours as SpatialLines")