Maps are tricky, especially quantitative choropleth maps. Not because they are hard to make in Tableau. Just the opposite, it takes just a few mouse clicks to make one but is it right? It depends on the data. When you drop a continuous measure on the Filled Map, Tableau creates a choropleth map and assigns a unique shade of color to each mark – a sequential color palette.
When your data is normally distributed, this default setup might be just what you need…
… but it often isn’t and the color assignment requires further exploration.
Overview of map classing
Cartographers use several different methods of aggregating features into classes, all with a single purpose of making spotting patterns in the data easier. The maps above are examples of Unclassified Scheme where every mark (polygon) with a unique data value receives a unique shade of grey…
READ THE WHOLE ARTICLE ON OUR MAIN WEBSITE
I run into this site exploring the possibility of defining custom classes in choropleth maps in Tableau. I am a new user to Tableau, but a fairly seasoned GIS and mapping specialist. I really liked the descriptions of different classification methods on this page, but I still cannot notice how such different classes can be implemented in Tableau. I am also not sure how Tableaupicasso relates to Tableau, if at all. Sorry for my ignorance, am I missing something here?
Thanks for your comment. These color classes are fairly easy to implement in Tableau. You can download the two Tableau workbooks shown in the post for your reference. Just look at the Color marks card on each map. There is either a calculated field there or a dimension with a sequential or stepped color palette applied.
Here are the direct links to these workbooks:
Hope this helps,