The Seven Bridges of Königsberg

Mar 292010

..or do geodevelopers require mathematics?

MyCircle.Area seems simpler.. Alan Skorkin has a great post on “you don’t need math skills to be a good developer but you do need them to be a great one.” Geo-technology developers have similar requirements, and the majority of GISs revolve around CRUD operations. However due to the nature of spatial data we occasionally get to meddle in the world’s of projections, geometry, typology, and set theory more than our counterparts in other sectors.

The Ancient Mysteries

There are now five bridges in Königsberg..Whilst concentrating on algorithms and recursion is a definite benefit to all developers, us spatial developers need a few more specific tricks.  Euler’s 1736 paper on Seven Bridges of Königsberg is one of the first academic writings on modern topology. The titles of these mathematics puzzles create an aura of mysteriousness and arcane knowledge that definitely sweetens the somewhat dour algebra underneath.

The solution (or non-solution) to this problem underpins many of the more advanced techniques used by GIS packages today. The “Travelling Salesman”, whilst conjuring up less interesting images, relies on similar principles of graph theory. Continue reading »

6 Tips for Developers Moving into GIS

Mar 162010

With the rise of the neogeographers, along with the increased awareness and use of GIS thanks to the web, more and more positions are open for developers looking to move away from writing business accounting logic, and into the exciting “new” world of spatial data. I’ve noticed a few gotchas that have happened to developers with no GIS background while working on projects, so this list may at least raise awareness of some of the hurdles.

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1. Get to Know your GIS Application

Most desktop development in GIS involves building extensions to an existing application using an existing programming library. In order to avoid reinventing the wheel you need to be able to use your GIS desktop package.

Before developing any automated tasks, manually go through the process to get a feel for any issues that may arise, and learn some of the terminology used by the program for the various functions. If the application has an option for hatched polygon fills, this option is also likely to be buried somewhere in the API. If you can’t find what you are looking for then run what you are trying to accomplish past a GIS user.

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7 Reasons for ESRI not to Drop VBA

Sep 272009

I recently learned from James Fee’s blog that ArcGIS 9.4 will be the last version that supports VBA. I can see why this is being dropped – Microsoft no longer promotes or updates VBA. Microsoft now promote “Visual Studio Tools for Office” as its replacement for VBA in MS Office products, however VBA is still in Office 2007, and looks to be kept in for at least the next version. Is ESRI acting too prematurely? I can think of 7 good reasons why VBA should be kept.

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1. VBA is great for prototyping. There is no need to open up Visual Studio, create a custom tool, implement all its interfaces and constructors etc. before you can even get round to writing the code for the OnClick event of a button.
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