Utilities for Updating Coastline/Border Data
============================================

This folder contains utilities for updating basemap's version of GMT's GSHHS
shoreline, river, and political border dataset.

The coastline, etc data used by basemap can be updated in two ways:

A) Download the GSHHS shapefiles and use them
B) Use GMT if you already have it installed, and avoid the download.

The preferred method is to use the GSHHS shapefiles.

Option A - GSHHS Shapefiles
---------------------------

1) Download the shapefile formatted versions of GSHHS and extract them in the
   "utils" directory. The data is available at: 
   https://www.soest.hawaii.edu/pwessel/gshhg/
   (Last updated with: ftp://ftp.soest.hawaii.edu/gshhg/gshhg-shp-2.3.5-1.zip)
2) Run readboundaries_shp.py.

Option B - Generic Mapping Tools
--------------------------------

1) Install GMT. Note that you may need to install a separate gmt-suplemental
   package to get "gmt gshhg" on some systems.  
2) Download gshhg native binary-formatted data from 
   https://www.soest.hawaii.edu/pwessel/gshhg/
   (Last updated using: ftp://ftp.soest.hawaii.edu/gshhg/gshhg-bin-2.3.5.zip)
3) run dumpbounds.sh to create states, countries, rivers text files.
4) run readboundaries.py to process into binary files, with metadata in
   separate text files.

Updating Landmask Data
----------------------

In most cases, you will not need to update the raster landmasks used by
basemap.  However, if GSHHS has had a large number of new islands or lakes
added, you may want to update the landmasks in addition to the vector data.

You'll need GMT installed to update the landmasks. Once you have it (and the
full-resolution GSHHS data, which is usually a separate package), run
``update_landmasks.py``.
