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Dealing with NULL values in Tableau filled maps – show null values in distinct color.


dealing with NULL values in Tableau filled maps

Anytime you create filled maps with certain dimension members (could be country/state names) having NULL values (missing values), Tableau tends to color or highlight the entire region regardless of whether countries/states have values or not - resulting to views which can be misleading to users.

This is what am talking about…

(In this filled map, the highlighted states contain NULL values, however by the look of the color legend they have been represented as if they contain values – which is misleading to users)

simple filled map in tableau

How can we fix this?

We can fix this by simply showing the states containing NULL values in a different color.

To do that, create a simple filled map.

Duplicate the view (map)

duplicating maps in tableau

Make the view dual axis…

dual axis maps in tableau

Create a calculation that will return TRUE for cases where states have NULL values (for this data am using Sales).

tableau calculated fields

Add this calculation to color shelf of the second view (chart), ensure the selection under marks card is ‘Map’.

showing null values in distinct color in tableau maps

Assign the appropriate colors.

On the color legend hide the item ‘False’.

And there we’ve a more interpretable view which users can easily tell the states with null values – take the right action without being misled by the view.

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