Erica kicked off the 1st year of #WOW2025 with a table calculation based challenge asking us not to just use quick tableau calculations, to avoid the use of the RUNNING_SUM table calculation and to just create 2 calculated fields.

Defining the calculations

On a new sheet, add Order Date to Rows as a discrete (blue) pill at the Month-Year format and add Sales to Text.

For the running total, we want

Running Total

SUM([Sales]) + PREVIOUS_VALUE(0)

which takes the Sales from the current row, and adds it to the value of the cumulative Sales (ie this calculation) in the previous row

For the moving average, we want

3 Month Moving Average

WINDOW_AVG(SUM([Sales]), -2, 0)

which averages the Sales for the current row plus the previous 2 rows (ie 3 rows in total)

Building the Viz

ON a new sheet add Order Date as a continuous (green) pill at the Month-Year format to Columns and Running Total to Rows.

Change the mark type to Area, and set the Colour to #a16eaf with a 25% Opacity.

Add Order Date to Tooltip, and set to the MIN aggregation. Format the pill on the Tooltip shelf to have the <month year> format when displayed on the pane.

Add another instance of Running Total to Rows. Set the Mark type to be Line and reset the opacity on the colour shelf to be 100%. Make the chart dual axis and synchronise the axis.

Add 3 Month Moving Average to Rows. Set the Colour to be #67c79c at 25% opacity.

The add another instance of 3 Month Moving Average to Rows. Set the colour to #67c79c and the mark type to line and increase opacity to 100%. Make dual axis and synchronise the axis.

Update the Tooltip on the All Marks card, referencing the MIN(Order Date) pill and adding $ before the values

Edit the Order Date axis, to start from 01 Jan 2021 and end on 31 Dec 2024. Remove the axis title.

Format the Order Date axis, and set the Dates on the scale to be formatted with the MMMMM notation to just show the first letter of the month

Add a reference line to the Order Date axis, set to be a constant value of 01 Jan 2021, with a custom label of 2021 and the line is formatted to be a white dashed line of 100%

Then format the reference line so the label is aligned top right

Repeat this step 3 more times, adding Reference Lines for 01 Jan 2022 (labelled 2022), 01 Jan 2023 (labelled 2023) and 01 Jan 2024 (labelled 2024).

Finally, hide the right hand axis (uncheck show header), remove column dividers, but show the axis rules on the rows.

And that should complete the challenge – just pop the viz onto a dashboard and publish. My published version is here.

Happy vizzin’!

Donna