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Add a Reference Line to a Discrete Headers


Published: 20 Jun 2014
Last Modified Date: 14 Dec 2018

Issue

Unable to add a reference line to a discrete field in the view. For example, adding a reference line on a histogram.

Environment

Tableau Desktop

Resolution

The directions for each example start from the corresponding "original" worksheet in the example workbook that can be downloaded from the right-hand pane of this article.

Option 1: Convert the discrete field to a continuous numeric or date field

  1. Select Analysis > Create Calculated Field
  2. In the Calculated Field dialog box that opens, do the following, and then click OK:
    • Name the calculated field. In this example, the calculated field is named "Sales Bins"
    • In the formula field, create a calculation similar to the following:
    • (FLOOR([Sales]/1655)*1655)
      Note: The above calculation is the same calculation that Tableau Desktop uses to generate bins. 1655 is the size of the bin.
  3. Right-click [Sales Bins] in the data pane and select Convert to Dimension
  4. Right-click [Sales Bins] in the data pane and select Convert to Continuous
  5. Replace [Sales (bins)] with [Sales Bins] on the Columns shelf
  6. On the Marks card, change the mark type from Automatic to Bar in the dropdown menu
  7. Add a reference line to the Sales Bin x-axis as normal. For detailed directions, see Reference Lines, Bands, Distributions, and Boxes
     

Option 2: Use a calculated field as a dual axis to mimic a reference line

  1. Select Analysis > Create Calculated Field
  2. In the Calculated Field dialog box that opens, do the following, and then click OK:
    • Name the calculated field. In this example, the calculated field is named "Mock Reference Line"
    • In the formula field, create a calculation similar to the following:
    • IF [Sub-Category]= "Chairs & Chairmats" OR [Sub-Category]= "Rubber Bands" THEN 1 END
  3. Drag [Mock Reference Line] to the Rows shelf.
  4. On the SUM(Mock... Marks card, do the following:
    • Change the mark type to Bar in the dropdown.
    • Click Size and adjust the width of the bars with the slider.
  5. Right-click the [Mock Reference Line] y-axis in the view and select Edit Axis...
  6. In the Edit Axis dialog, do the following and close the dialog:
    • For Range, select Fixed
    • Set the range from 0 to 1
  7. Right-click [Mock Reference Line] on the Rows shelf and check Dual Axis.
  8. Right-click [Mock Reference Line] on the Rows shelf and uncheck Show Header.

     
 

 

Cause

The ability to add a reference line to a discrete field is not currently available in Tableau Desktop. 

Additional Information

See the attached example workbook for a variation of Option 1 using dates.
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