EXERCISE 11 – Odds and Ends
Environmental Resources 372:362
Intermediate Environmental Geomatics
We've seen over the course of the semester that ArcGIS can do a whole lot of things. Sometimes, though, it doesn't give us an easy way to perform the task or tasks that we need or want to do. If we were Visual Basic programming whizzes, we could use that language to create the tools we need from the building blocks that ESRI provides. Fortunately, for those of us that aren't VB whizzes lots of people who are make their scripts available through ESRI's website, and adding other people's custom scripts to ArcGIS is really easy.
At http://arcscripts.esri.com, we can search for user contributed scripts that might help us simplify our lives, or at least our GIS work. You can search for scripts by keyword, language and/or ESRI program they work with. Scripts can be saved in a number of different formats. Some are saved as .dll files. These are very easy to load and usually come with information about how to do it. Unfortunately, you can only load them if you have administrator rights to the machine you are working on. We don't, so we can't use this type of script in this class. Perhaps they'll fix this issue in the next version. They're so easy to load you'll have no trouble figuring out how to use them if you ever have an opportunity to use them.
We can use another type of script, stored as a .txt file, that requires a bit more work. Let's say we're interested in finding such a script that will report to us the area of selected polygons in some unit more reasonable than square map units.
On the ESRI website, search for scripts using "area" as the keyword and ArcGIS Desktop as the program. Among the results returned by the search, the one written by Pete Aniello sounds like it might do what we need. Clicking on its name gives us more information about it, verifying it's what we want. Click on download, accept the agreement and save the zip file to your directory. Once it's downloaded, double click on the zipfile and extract the script to your directory. The scripts usually have a README file containing instructions and information about the script. It's a good idea to read it. The readme file for this script tells us that it reports the total area of selected polygons in square km, and that the data units of the layer we run it on should be in meters.
Once it's extracted, we need to add it to ArcMap. The text files are a bit more difficult to add than .dll filles. Start ArcMap. Open the Visual Basic Editor (Tools->Macro->Visual Basic Editor). Find the directory tree like display up the left corner and open Module 1 under Normal.mxt. Open the downloaded script in Notepad, then copy and paste into the Module 1 window. Before we run it we need to load a polygon theme into the ArcMap data frame (try /databank/njdep/admin/stmun). Select a some municipalities, then return to the Visual Basic Editor. Click on the run button (right pointing triangle) to execute the script.
The Arcscripts website is a very handy resource. Anytime you're faced with a task that it seems like ArcGIS should be able to do, but for which no pre-existing command exists, take a few minutes to search the script repository. It just might make life a whole lot easier for you. Don't discount your ability to hack scripts, either. Even if you don't know VB it's often not that hard make a script that almost does what you want do exactly what you want.
2. Intro to Plotting
After being introduce to the plotter, you should be ready to take your first steps in using it, if you dare. Before actually sending a layout to the plotter, remember to double, triple, even quadruple check it. Print out a 8"x11" test copy to get an idea if you layout works well enough to send to the plotter. The paper and ink the plotter uses are considerably more expensive than those for the other printers.
Extra Credit: You are going to form into teams and plot out a poster. It will be an ANSI C-size plot (~17x22).
You will assemble these as a team project. Your team will have either 3 or 4 people. None of them are on your other team.
You will pick a County and sign-up to avoid repeats.
Your poster will include three different maps of the county. The largest map would be a road map, hopefully good enough for navigation. Maybe it would include labels from the geoplacenames list. Maybe it would include municipal boundaries. Railroads? You figure it out.
The second map would show the major natural features (Streams? Lakes? Terrain?)
The third map should be the smallest. It should show something else. Land
use? Open Space? Census data?
Here's the thing about extra credit: something is worth more than nothing. Almost any C-size map will be better than sitting at home. Here's the other thing: If you waste 20 hours fussing over a map that is worth so little, your final project team deserves a divorce. Whatever you do, do it quick.
Extra Credit due Monday, April 25th.