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Maps are Just Another Element
Posted By Graham Wills on Feb 10, 2009 at 03:02 PM
Filed Under Clementine, Grammar of Graphics, SPSS Statistics v17, Visualization
For the VizML visualization system used in SPSS products, maps are simply another element that can be used within the grammatical formulation.
Although most people consider a map a very different entity from a bar chart, all that really differs between a bar chart and a map of areas like the one included here is that instead of representing a row of data by a bar, we use a polygon (or set of polygons) on a map. Otherwise their properties ought to be the same — we can apply color, patterns, labels, transparency. We can set a summary statistic when there are multiple values for each polygon to reflect min, max, mean, median, range, or any of the regular sets of items. We can flip, transpose and panel the charts. Essentially, from the grammatical point of view, if you can do it to a bar chart, you can do it to a map. The only limitation is that whereas the sizes of the bars can be set or determined by data, the map polygons cannot, so setting sizes on the map polygons has no effect.
The above chart can be created within SPSS Statistics and Clementine, using the Graphboard Template feature. The template was created in Viz Designer, but you don’t need that tool simply to use a template. Following is a chart showing cell-phone ownership on a per-capita basis for countries throughout the world.
At the end of this post is a zip file containing the templates used to build these two charts. Unzip it on your local machine and then, within the Graphboard Template Chooser dialog, click the “Manage” button to import them. Do that once from any application ,and they will be installed and ready to use in all your graphboard-enabled SPSS applications. All the templates only need a variable with the names in them (Illinois, Alaska etc. or Germany, France, etc.) — color, labels and transparency can be attached using the optional dialog.
If you have a copy of Viz Designer, you can modify and enhance these templates in many ways. If you don’t and you’re an XML whiz, you could even try opening the templates in your favorite XML editor and modfiying them directly. The worst that’ll happen is a useless template that’ll fail to load, or draw strange results. Let us know how you get on if you try that method out …
And here are the templates, ready to download and install …
Map Templates
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Comments
4 Responses to “Maps are Just Another Element”
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I tried downloading the zip files for this post, but I am getting an error that the page is not found. I know you just moved your blog, so I just wanted to give you a heads up.
The attachments should be okay now. Thanks for letting us know.
Hi, this looks interesting. Does it just look like GIS, or is it really GIS? It would be nice if existing Shape-files could be used.
AJ
There’s an intersection of what we do with what GIS systems do, but they have very different purposes and hence different features. For example, we have a ton of features for showing statistical information on map elements, but not as much on traditional GIS tools like “show all cities with 10km of a road”. We do have multiple layers of data, filtering other functionality, and our (internal) tools allow us to read ESRI shape files, but at present we don’t have a way to let our customers use them. But your request has been noted!