Shading between Lines in Tableau makes your simple visualization looks cool.
While there is a detailed post on Shading between lines using LOD’s from DataSchool UK – Click Here, I tried to give a shot on this in three ways – Table Calculation , Simple Calculated field and LOD.
Option 1: Using Simple Calculated field
My Dummy Data Source contains 3 Column’s (Date by quarter, GDP and Public Debt)
The Following Steps are relevant for all the options with this data source


 Move the Quarter to Columns Shelf
 Change the Quarter to “Exact Date”
 Add the Quarter to filter Shelf and filter by Date Range from 1991 to 2020 (For demonstrations only)
 Move the measure values to row shelf.
 Move the Measure name to filter and select only “GDP”, “Public Debt” and the Calculated field created to find Minimum Value per year.
 Change the Marks to Area
 In Analysis menu, click on “Stack Marks” and select only “Off”

The theory behind shading between lines is finding the minimum value between two measures/two dimensions for the given date and coloring the area formed to match with worksheet color. (Jargons – finding the Inner join Area between the two Values)
To find the minimum value between the two measures in the connected data source the following formula to be used.
IF MEASURE1 > MEASURE2 then MEASURE1 ELSE MEASURE2 END
Drag the Calculated field “Min Value Per Year” to the Measure Values, and Measure names to color shelf, change the color of “Min Value per year” to match that of work sheeet shading.
Option 2: Using Table Calculation
The Table calulation and LOD need a dimension against the values to compute. Hence, I had Pivoted the above data source by pivoting GDP and Debt column in the Data source. (In the Data source sheet, Highlight two column’s and right click to select the Pivot option)
Now, go to new sheet and do the following


 Drag Quarter to columns shelf
 Drag Values to Row shelf
 Description to the Marks card and change it to “color”
 Other formattings – same as option 1.

To find the minimum value between the dimension for the given date(Quarter) by table calulcation we need to use “Window_Min” formula in the calculated field and select the order of calcualtion in the table calculation option.
To explain above calculation in simple English, I would say – for unticked dimension “Quarter”, calculate minimum value in ticked dimension “Description”.
Once the calculated field with above formula is created , drag it to measure value and change the order of table calculation.
Finally, change the color of area formed using minimum value to the white as to match the shading of Worksheet.
Options 3 : Using LOD (Level of Detail)
As mentioned at the beginning of the blog, there is a detailed explanation on this topic from DataSchool UK (Please check the above for the link)
For the purpose of this demonstration I will be using FIXED LOD function to find the Minimum value within dimension. The Syntax for this as below:
{FIXED [DIMENSION] : AGGREGATE([MEASURE])}
{FIXED [Quarter] : MIN([Value])}
The steps after this follows similar to the option 2:
Dual Axis Tweaking
After Creating the shading between the lines, the overall visualization can be further enhanced by creating the outline of the area using dual axis method.


 Drag the Values to the ROW shelf in addition to the Measure Values
 Change the chart ype of SUM(Values) to Line.
 Remove Measure names from the Color in the SUM(values) Marks Shelf
 Right click on the SUM(values) and select Dual Axis
 Right click on the axis label and select “Synchronize axis”
 Change the shades in Area Marks to lighter than the Line chart, so the line clearly stands out of area chart after Synchronize.

Feel free to post any suggestions or improvements, I generously accept complements , if you do have one, please drop below.