| nepacLL {PBSmapping} | R Documentation |
PolySet of polygons for the northeast Pacific Ocean shoreline.
data(nepacLL)
Data frame consisting of 4 columns: PID = primary polygon ID,
POS = position of each vertex within a given polygon, X
= longitude coordinate, and Y = latitude coordinate. Attributes:
projection = "LL".
In R, the data must be loaded using the data function.
In S, the data are loaded automatically on demand.
Polygon data from the GSHHS (Global Self-consistent, Hierarchical, High-resolution Shoreline) database.
We thinned the full resolution GSHHS binary data with a tolerance of
0.2 km and then converted it to ASCII data using the supplied software
(gshhs_dp.exe and gshhs.exe, respectively). Using a
Perl script (gshhs2r.pl), we then converted this ASCII format
to ours, removed the lakes, islands in lakes, and ponds in islands,
and filtered out any islands with fewer than 15 vertices. We then
clipped the data to 170 <= x <= 250
degrees and 34 <= y <= 72 degrees
(the GSHHS coordinates roughly span 0 degrees to
360 degrees). Finally, we subtracted
360 degrees from all of the remaining
x-coordinates, so that the Greenwich meridian becomes
0 degrees and the northeast Pacific Ocean has negative
x-coordinates corresponding to longitudes west of 0
degrees.
Wessel, P., and W.H.F. Smith. 1996. A global, self-consistent,
hierarchical, high-resolution shoreline database, Journal of
Geophysical Research 101: 8741-8743.
http://www.soest.hawaii.edu/pwessel/pwessel_pubs.html
addPolys,
bcBathymetry,
clipPolys,
nepacLLhigh,
plotPolys,
plotMap,
PolySet,
thickenPolys,
thinPolys.