Blog Category

Invalid Geometries

Posted in Database, Open Source GIS, Techniques on Jun 08, 2022

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.

Never Too Late to Tessellate

Posted in Database, Open Source GIS, Techniques on Dec 07, 2021

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 Aug 12, 2021

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, 2021

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

A Trigger-Happy Solution

Posted in Database, Techniques on Sep 27, 2019

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, 2018

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.