PostGIS
Spatial and Geographic objects for PostgreSQL
Upcoming Events
Recent past events
Sep 13-15 2016 Dallas, TX, US
Tips
Selecting only pixels of particular range of values with ST_Reclass
This raster question comes up quite a bit on PostGIS mailing lists and stack overflow and the best answer often involves
the often forgotten ST_Reclass function that has existed since PostGIS 2.0.
People often resort to the much slower though more flexible ST_MapAlgebra or dumping out
their rasters as Pixel valued polygons they then filter
with WHERE val > 90,
where ST_Reclass does the same thing but orders of magnitude faster.
Case Studies
Nautilytics Case Study
Nautilytics is a small data visualization and GIS startup based out of Boston, MA. We use PostGIS and PostgreSQL, among other open-source tools to build powerful web applications for US government organizations, public, and private sector companies.
PostGIS for fast prototyping and Research
I used extensively postgis (+ecosystem) for my phd thesis, in several ways. The first is that PostGIS is a good steady horse (elephant?): a database is the perfect place to store a lot of very different information in the same place and put them in relation. For geospatial data, postgis means you always have a way to put data in relation (are they at the same place?).