Coastline Extractor
Making Continuous Coastlines
(or other types of lines!)
Fragmented coastline segments can be concatenated to form
continuous coastline pieces using a MATLAB routine
"join_cst.m". Join_cst starts at the end of the first segment
and attempts to append the segment with the nearest endpoint that
is within a specified tolerance of the first segment endpoint.
It continues adding segments until no more are within a tolerance
of the last end point. It then goes back to the beginning of the
first segment and attempts to append segments. When no more
segments can be found within the tolerance, it starts a new
segment, and continues generating contatenated segments until all
the original coastline segments have been used. It then sorts
the newly concatenated segments into descending order by size.
Thus the coastline is usually the first segment, followed by
large islands, then smaller islands, etc.
This sorted coastline is ideal for
blanking or filling purposes, as all islands will be polygons that can
be filled, and the coast can be turned into a polygon with a few extra
points.
Get the m-files!
- Download joincst.m and place in a directory accessible to Matlab.
- Type "joincst" in Matlab to "unbundle" the collection of files.
- Type "help join_cst" in Matlab for instructions on use.
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