topic Re: Geographic Density Heat Map in Graphics Programming

Geographic Density Heat Map

newnoise — Thu, 06 Oct 2016 21:10:06 GMT

Is it possible to make a map like the one below in SAS? I can't find any examples of such a map online nor any SUGI proceedings on it.

Looks like it'd be a contour plot by coordinates overlaid on a projected map. But how do you go about doing that? Is it possible?

Any help would be greatly appreciated.

Re: Geographic Density Heat Map

ballardw — Thu, 06 Oct 2016 23:12:14 GMT

Here's a link with one form. though the data is precipitation the principal could be the same: http://robslink.com/SAS/democd82/precipitation_map_10inches_info.htm

And here's one using smaller regular filled circles to simulate a larger area

http://robslink.com/SAS/democd75/solar_potential_map_info.htm

Explore Robslink.com for many examples of graphs and maps.

Re: Geographic Density Heat Map

Rick_SAS — Fri, 07 Oct 2016 13:45:21 GMT

See the paper and references in

Massengill and Kolovos (2012) "Together at last: Spatial analysis and SAS mapping"

Re: Geographic Density Heat Map

newnoise — Fri, 07 Oct 2016 14:17:57 GMT

This is great! Thanks for passing along!

Re: Geographic Density Heat Map

Darrell_sas — Fri, 07 Oct 2016 14:54:00 GMT

Basically, there are 2 ways to do it and neither are easy without the proper data.

First, there is making the heat map with annotate. You have to draw the heat map in the correct locations. The examples that Ballardw and Rick suggested are using annotate.

Second, there is a counties map. If you have the data per county, you can do something like this weather map:

Re: Geographic Density Heat Map

newnoise — Fri, 07 Oct 2016 15:19:25 GMT

Thanks for the suggestion! We have county-level data, but I didn't want the unit of analysis to be county, as they can be rather large, particularly out west. I wanted to be able to use our point-level coordinates to get densities around specific areas, regardless of state or county lines. I think the Massengill and Kolovos (2012) paper gets me where I want to go. It's not simple, but it looks like it'd get the job done.

Re: Geographic Density Heat Map

ballardw — Fri, 07 Oct 2016 16:35:06 GMT

You don't mention what the heat map is actually intended to display. Please note that in those "big counties out west", since I work with such data, that many interpolations across those areas can be extremely misleading. In some cases related to characteristics of people because there are no people resident in the area and for phyiscal characteristics such as weather phenomena that elevation often has a large influence on results.