1.6 KiB
Wang–Müller algorithm in PostGIS
This is a work-in-progress implementation following "Line generalization based on analysis of shape characteristics" by Wang and Müller, 1998 paper.
Structure
Detailed implementation description: mj-msc.tex
. It is describing in detail
what is implemented and what isn't, and why.
Algorithm itself: wm.sql
. This is the main file you probably want to look at.
Synthetic tests are in tests.sql
. They are exercising various pieces of the
algorithm and asserting the results are what expect them to be.
Tests with real rivers are in test-rivers.sql
.
Makefile
glues everything together.
Executing the algorithm
$ make help
mj-msc-full.pdf Thesis for publishing
test Unit tests (fast)
test-rivers Rivers tests (slow)
clean Clean the current working directory
clean-tables Remove tables created during unit or rivers tests
help Print this help message
wc Character and page count
refresh-rivers Refresh rivers.sql from Open Street Maps
To execute the algorithm, run:
make test
for tests with synthetic data.make test-rivers
for tests with real rivers. You may adjust the rivers and data source (e.g. use a different country instead of Lithuania) by changing theMakefile
and the test files.
Building the paper (pdf)
mj-msc.tex
results in mj-msc-full.pdf
, which will be at some point
published. It needs quite a few dependencies, including a functioning Docker
environment.
License
GPL 2.0 or later. Same as QGIS and PostGIS.