I'm drawing a geo heat map, whose geographical level is DMA.
Now I have:
DMA level data
Mapping of STATE-DMA-COUNTY (as you know, counties are nested in DMAs)
I can easily get a map like this (the numbers are DMA codes):
But I don't know how to draw borders for these DMAs (the borders are for STATEs). I need that is because after the metric data is loaded, some DMAs will be filled by a same color, and we can't separate them any more.
I read the info about geocoding, however:
It requires longitude/latitude info (which I don't have)
I just need to merge some counties to a DMA, and counties are already recognized by Tableau.
This task sounds not that hard, but I haven't figured out how to do that.
For anyone looking to create Designated Market Areas (DMA) in Tableau, you should be able to use Custom Territories. I've received sample data from Nielsen that includes DMA by Zip Code. All you have to do in Tableau v10 is assign the DMA field to be based off the underlying Zip Code.