Blog Category

Never Too Late to Tessellate

Posted in Database, Open Source GIS, Techniques on Jul 07, 2017

This is the final post in the simplification series.  It reveals a new way to restore the congruent fit of a polygon layer after it has been simplified.

On Topo the World

Posted in Database, Open Source GIS, Techniques on Jun 12, 2017

What is topology and why does it matter?  This post continues to explore the complications of simplifying GIS data.

Why Simplification Is Complicated

Posted in Open Source GIS, Techniques on May 24, 2017

Efficiency and resolution go hand-in-hand.  This post challenges the accepted best practice for simplifying vector graphics for use at smaller scales.

Invalid Geometries

Posted in Database, Open Source GIS, Techniques on May 08, 2017

How can a geometry be invalid?  It sounds impossible but it can happen.  Fortunately, invalidity is not at all fatal.  Once you understand the problem, fixing it is easy.

A Trigger-Happy Solution

Posted in Database, Techniques on Mar 27, 2017

How can you change the symbol used to draw a feature on your map when a new record is written to a related table?  A smart database can do that for you.

Getting to the Point

Posted in Android, Techniques on Mar 13, 2017

Virtually all Android mobile devices have a a magnetic field sensor (or magnetometer).  So why would developing a compass control be so challenging?  Take a quick peek under the hood and find out.