I wish to use PostGIS/PostgreSQL for data mining exercise (MSc project) rather than developing fully-fledged GIS app, the goal being to determine the causes of water quality issues in a water distribution network. I need to: - filter and pre-process several datasets (each containing ~10^5 records) describing water quality issue events and possible cause events - associate the events in different cause and effect datasets with edges/nodes in my distribution network model to produce an ‘integrated network model’ - traverse the network model, giving consideration to the network hydraulics, in an attempt to associate one or more possible causes with each water quality issue.
I believe I can achieve most of this using ‘standard’ SQL, PostGIS functions and possibly some recursive PL/pgSQL functions to traverse my network structures and then visually verify that the region of influence determined for each water quality event is sane using Quantum GIS. However, I would very much like to automate aspects of the dataset processing, integrated model construction and model analysis to allow me to more easily perform sensitivity analysis on certain parameters, to reduce the amount of ugly adhoc snippets of (say) Python that I need to write and to perhaps allow the analysis parameters to be set and the results viewed from a QGIS plugin. I’ve considered baking lots of SQL into pyodbc cursor.execute(sql) calls but think that such an approach could get rather messy. I’ve also taken a look at the SQLAlchemy/GeoAlchemy ORM framework, which initially seems to be rather too heavy for my needs and would require me to spend much time finding ways to rewrite complex queries involving many joins and much nesting. I should also mention that I have little time to devise an analysis tool and generate some results and that I haven’t done much programming (OOP or otherwise) for a number of years. How do other list subscribers manage data analysis projects (as opposed to full-on GIS application development projects) using PostGIS? How far into writing ORM code or integrating an existing ORM framework have people gone when undertaking similar tasks? _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
