You’re going to hear the term GIS a lot when it comes to mapping - that stands for the boring term Geographic Information System, which is a.k.a. the very exciting term “cool maps and geographic analysis.”
If you’re doing GIS work, you’re going to be using some sort of GIS software. Your two options are
The term shapefile is a little misleading - yes, there’s usually a
.shp file that’s the guts of the shapefile, but a proper shapefile comes zipped up with all sorts of friends.
.shpis the geometry for the data - polygons, points, you name it.
.prjis the projection used, as latitude and longitude don’t quite cut it in the GIS world.
.dbfis the data associated with each point, line polygon. Think state names, population data, or the year a house was built.
.shxis an index file for the
.shp’s geometry (a.k.a. helps speed things up)
.shp.xmlis “geospatial metadata in XML format,” but I don’t know what exactly follows from it
There are many more, but the ones above are the ones you’ll see most often. They know they’re related because they all share the same name. Let’s say I was trying to get a shapefile for the united states, I might have
United_States.zip, which extracts to contain
In order to open shapefiles, you’ll probably want to install a GIS program. Let’s give QGIS a run, seeing as how it’s 100% free.
Hop on over to the QGIS site and you’ll be able to download it lickity-split.
There’s bad news and good news.
If you went to the QGIS download site you’d get the same information, so I’m just going to put it all here.
Let’s get installing!
QGIS depends on something called GDAL, the Geospatial Data Abstraction Library. Let’s install it!
Now back to the main install page - download QGIS and see if you can download it and get it to run. More problems? Missing
matplotlib? Download anything else you might need from the main install page or the frameworks page until QGIS successfull opens (I was just updating QGIS and I needed the new SQLite3).
NOTE: If you know what Homebrew is, you might try to use
brewto install GDAL. Unfortunately, this won’t work! QGIS uses the GDAL Complete package and will totally ignore Homebrew’s GDAL. If you don’t know what Homebrew is don’t worry, just let your eyes glaze over.