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Justin, I'm just stopping by for a quick Sunday Afternoon Fun Ride, but it seems to me I remember congressional districts were recently added to Tableau geography as a 'native' geography, back during the election -- I could be wrong on this.
--Tableau Tableua (aka Shawn)
If you already have the latitude and longitude of each address, it sounds like what you need to do is a spatial join, e.g. add the house and congressional districts as data columns. You can do this in Quantum GIS, an open source GIS software package. Here is a tutorial on how:
Warning: there are potential pitfalls
... the greatest being that your shapefiles need to be defined in the same projection in order for the operation to work. You can check this by opening the .prj file associated with each shapefile in a text editor and comparing the text. If they are NOT in the same projection, you will need to reproject one or both files.
That may be how I solved the problem (although not knowing what I did or that it was called a spatial join.)
So as not to be that person that solves a problem and doesn't share, I will explain what I did in non-technical terms (since I don't know what they are, and it has been a while since I did it) for future reference.
I opened the shape files I obtained from one of the state legislative branches using Quantum GIS. Then, I added another layer with the lat/lon of the addresses I had making sure they were on the same projection (WSG84 for some reason is stuck in my head although the order of those letters may be off). Finally, I was able to extract which points fell into each district by exporting from QGIS (sorry don't remember exactly what I did). Finally, I fed that list into Tableau to aggregate by district, and ultimately make a really cool document with contact info, the picture of the congressman, and stats for the number of our students that were in each district.
PS I did this only for the Oklahoma districts.
Ok cool! It sounds like you found a solution and I'm glad to hear it.
Would you mind sharing this workbook with me? My email address is mluttonATgoodwilleducationDOTorg; thanks!
I wouldn't mind at all, except the Tableau part of it didn't have anything to do with the actual locating students within districts. Basically I used QGIS to add a district number onto each row of student lat/lon information. Then, QGIS generated a CSV that I fed to Tableau to count the number within districts based on that CSV.
That's OK, I'd just like to see it as an example. Please email me at my address if you can.