Find Neighbor Polygons using Summary Aggregate Function in QGIS

Read my previous posts Summary Aggregate and Spatial Filters and Advanced Aggregate Expressions to Automate QA to learn more about the powerful aggregate function. The aggregate function in QGIS was designed to work with 2 separate input vector layers, but we can also make it work with a single layer. Essentially performing spatial queries for … Continue reading Find Neighbor Polygons using Summary Aggregate Function in QGIS

Advanced Aggregate Expressions to Automate QA in QGIS

This post is the continuation of Summary Aggregate and Spatial Filters in QGIS. I have been exploring aggregate functions more and have found interesting ways to automate tasks in QGIS. One such example is helping automatically keeping track of feature edits to help with Quality Assurance (QA). Problem Statement: Users are editing multiple layers in … Continue reading Advanced Aggregate Expressions to Automate QA in QGIS

Convert between UTM and Degree coordinates using Google Spreadsheets

Converting between different coordinate reference systems or projection is a fairly standard feature in a GIS. There are a number of command line tools also available for performing bulk-conversions. cs2cs program, part of the PROJ.4 library is my favorite. Recently, someone presented me with an interesting challenge. They were collecting field data in UTM coordinates and needed … Continue reading Convert between UTM and Degree coordinates using Google Spreadsheets