Node Dangles

As someone who lives in the boon-docks whose street (both my current and previous one) does not appear in the data for either NAVTEQ or TeleAtlas and someone who used both of those data sets extensively in his previous job, I’ve watched OpenStreetMap for awhile, although have not contributed. Marten Hogeweg, ArcGIS Server Geoportal Extension Product Manager, ESRI announce in his blogs an ArcGIS Editor for OpenStreetMap. Sounds like a great idea, giving GIS professionals–some whom have the source materials the ability to easily contribute should only help the project.

The USGS updated a significant portion of NED data for my state in June.  I recently downloaded the updates, processed them–projecting and converting the elevations from meters to feet–using python and geoprocessing.  My python skills are still pretty crude but I was able to get the job done.

One of the benefits of working for the public sector is that I can more freely publish code without worrying about ‘trade secrets’ or what have you so I thought I would put my code out for anyone to see, maybe someone will find it useful.  It is split into two separate files, mostly because I used Model Builder to generate the main processing chunk of code (Project_Reclassify.py) and another script to control looping, etc. The code isn’t pretty and you’ll see the results of my development process with two subroutines in LaunchScript.py that could really be one.

While I am pretty experienced in editing data in previous generations of ESRI’s software, I have not done a lot in ArcGIS. So in my new position where I am supporting a group of geologists who do a lot of data creation in ArcMap, I am learning some of the intricacies of the ArcGIS platform. One of the potential gotchas that a coworker informed me about that I was vaguely aware of was the issue of sticky move tolerances.

Came across a new ArcMap bug today. A staff member was trying to join an Excel 2007 file (.xlsx) to a point shapefile in ArcMap and it did not appear to be working. She only had Office 2003 on her machine so I tried it on my spanking new machine that has 2007 installed. Same result–the fields get appended but they are all blank. I discovered, however, that when I had the table open, if I switched form showing ALL records to only the selected, Poof!

In the last couple months, I’ve had a bit of an eye-opening about Geography. People actually trained in geography may implicitly understand this but I, with my Accounting degree, have spent the last 16 years ‘doing’ GIS without realizing the foundation of geography–geology. I picked up enough geography to understand some of the inter-relationships between people and the lands they live on. But what I didn’t pick up on was how the lands we live on are formed.

I recently had the need to calculate the distance from a point (address point) to a polyline (street segment) and wanted to avoid using any additional libraries because it was being done for an external client. Ok, I actually used arcgisscripting for reading the data but that lacked, from what I could tell, the fine-detail granularity of measuring distance between individual geometries. But since the only spatial operations I needed were to measure the distance between two points and the distance between a point and polyline, I decided to just do it via brute force.

I worked in Avenue for many years but do not expect to do too much more. Before my Avenue skills erode to nothing, thought I would share my favorite Avenue snippet. Really, it involves two ‘function’ scripts that clients scripts can use. What I got use to doing is instead of using a mess of global variables is using one global variable–a dictionary–that was used to store what essentially became global variables.

I spent almost nine years working for a great company, Applied Data Consultants!, through a variety of roles–spent approximately 3 weeks doing Parcel work as a GIS Tech before I started working in Avenue for my own sanity. After that, spent several years doing various programming tasks including building tools for internal production and application development. The last couple years, I served more of a Consultant role, both for internal and external clients.