Averaging Home Values in Google Earth

April 17, 2009 4:20 PM

GoogleEarthFilter: I have a bunch of addresses with the value of each house and want to average the values based on region.

I plotted all the addresses in Google Earth using an .xml file generated from http://www.batchgeocode.com/. I put the home values in the "Name" column so that it would come up when I moused over the point.

At the least I need to be able to: Draw in lines in Google Earth to show where voting districts are.

It would be awesome if I could: Draw in lines in Google Earth, maybe shift some data from the .xml file around, and have Google Earth figure the average home in each district value for me.

I can't import the voting districts map because it only exists in print form. If it matters, I have about 100 different addresses and the most updated free version of Google Earth.

Thank you!

posted by thewestinggame to computers & internet (5 comments total)

To draw the lines, all you need to do is use the path tool. If you are importing the data for the voting districts it would need to be in a standard format, you may have to convert it to a kml(xml) file, but in the end it is just a list of points which form each polygon. Just open up one of these files in a text editor, the format is pretty clear, and you can look at the docs for KML on google's site.

As to calculating the values, not sure if google earth is capable of that kind of thing, ideally you would use a GIS program like ArcGIS but it's very expensive. There is grass GIS which is open-source but it can be tricky to use. If you have programming skills, you could write a simple script to do the math and create the kml file yourself. To calculate the average property values, you would just need an algorithm to figure out if a point is in a given polygon. I'm sure there are other GIS/statistics packages that would do this simply but I'm not familiar with them.
posted by martini at 7:16 PM on April 17

You say here that you're still in college. Go to your geography department and use their computer lab - they'll have ArcGIS. Offer to take a geography TA out for coffee and he or she might do this for you, as it's a really trivial operation in ArcGIS.

Also, they might know where to get the voting files in digital form. Hit up your urban planning department. Google "yourtown GIS" and you might be surprised at what you can find.
posted by desjardins at 8:32 PM on April 17

Great! This is going to be much easier than I thought. Thanks!
posted by thewestinggame at 9:14 PM on April 17

ArcExplorer is a free application from the folks that make ArcGIS. I haven't played with it in a while, but the documentation on the existing version makes it sound as though it will do what you need. It will be more work than bribing a TA with coffee, but if you have the inclination and time you will certainly get more out of the experience. (Unless you really hit it off the with the TA, I suppose). Playing around the data, even in a light GIS like ArcExplorer, might spark some ideas for other analyses. Who knows, you might like it so much that it may inspire you to take a GIS class.
posted by mollweide at 7:38 AM on April 18

You could also try the free program Geoda

You will need shapefiles of the region, in addition to your geocoded addresses. It's a lightweight GIS program, but very easy to use and good for statistical analysis. I'm not certain how it deals with XML - the addresses might need to be in a csv file.

Otherwise, n-thing ArGIS. I think Geoda would probably be easier to use than ArcGIS, but I don't think you can export a kml file from Geoda, while you can using ArcGIS.
posted by a womble is an active kind of sloth at 4:44 PM on April 19