| read.coastline {oce} | R Documentation |
Read a coastline file in mapgen, matlab, or Splus format
read.coastline(file,type=c("R","S","mapgen"),debug=FALSE)
file |
Name of file containing coastline data. |
type |
Type of file, one of "R", "S", or "mapgen" |
debug |
Set to TRUE to print information about the header, etc. |
The S and R formats are identical, and consist of two columns, lon and lat, with land-jump segments separated by lines with two NAs.
The MapGen format is of the form
# -b -16.179081 28.553943 -16.244793 28.563330BUG: the 'arc/info ungenerate' format is not yet understood.
An object of class "coastline",
which is a list containing
data |
a list containing
|
metadata |
a NULL item that may be used in a future version. |
processing.log |
A processing log, in the standard oce format. |
Dan Kelley
The NOAA site http://www.ngdc.noaa.gov/mgg/shorelines/shorelines.html is a good source for coastline data files.
The generic function read.oce provides an
alternative to this. Coastlines may be created from
latitude/longitude pairs with as.coastline, summarized
with summary.coastline and plotted with
plot.coastline.
## Not run:
library(oce)
cl <- read.coastline("7404.dat")
# If no plot yet:
plot(cl)
# To add to an existing plot:
lines(cl$data$longitude, cl$data$latitude)
# Note: another trick is to do something like the following,
# to get issues of whether longitude is defined in (-180,180)
# or (0,360)
lines(cl$datas$longitude, cl$data$latitude)
lines(cl$data$longitude-360, cl$data$latitude)
## End(Not run)