read.coastline.shapefile: Read a coastline File in Shapefile Format

In oce: Analysis of Oceanographic Data

Read a coastline File in Shapefile Format

Description

Read coastline data stored in the shapefile format (see reference 1).

Usage

read.coastline.shapefile(
  file,
  lonlim = c(-180, 180),
  latlim = c(-90, 90),
  encoding = NA,
  monitor = FALSE,
  debug = getOption("oceDebug"),
  processingLog
)

Arguments

file	name of file containing coastline data (a file ending in .shp) or a zipfile that contains such a file, with a corresponding name. The second scheme is useful for files downloaded from the NaturalEarth website (see reference 2).
lonlim, latlim	numerical vectors specifying the west and east edges (and south and north edges) of a focus window. Coastline polygons that do not intersect the defined box are skipped, which can be useful in narrowing high-resolution world-scale data to a local application.
encoding	ignored.
monitor	Logical indicating whether to print an indication of progress through the file.
debug	set to TRUE to print information about the header, etc.
processingLog	if provided, the action item to be stored in the log. (Typically only provided for internal calls; the default that it provides is better for normal calls by a user.)

Value

x a coastline object.

A hack for depth contours

The following demonstrates that this code is getting close to working with depth contours. This should be handled more internally, and a new object for depth contours should be constructed, of which coastlines could be a subset.

Author(s)

Dan Kelley

References

1. The “shapefile” format is described in ESRI Shapefile Technical Description, March 1998, available at ⁠https://www.esri.com/content/dam/esrisites/sitecore-archive/Files/Pdfs/library/whitepapers/pdfs/shapefile.pdf⁠ (last checked 2021-03-24).

2. The NaturalEarth website ⁠https://www.naturalearthdata.com/downloads/⁠ provides coastline datasets in three resolutions, along with similar files lakes and rivers, for borders, etc. It is highly recommended.

See Also

Other things related to coastline data: [[,coastline-method, [[<-,coastline-method, as.coastline(), coastline-class, coastlineBest(), coastlineCut(), coastlineWorld, download.coastline(), plot,coastline-method, read.coastline.openstreetmap(), subset,coastline-method, summary,coastline-method

oce documentation built on Sept. 11, 2024, 7:09 p.m.