Vizible Difference

[ This is a guest post by Hans Romeijn. This is a followup post to my recent post on calculating YTD/YoY, QTD/QoQ, MTD/MoM and WTD/WoW. Hans shows a practitioner's approach to the calculation with performance in mind. The key is to replace conditionals by multiplications with pre-calculated indicator 1 or Null. This can accelerate the calculations significantly, especially when the data set is big.

The companion workbook courtesy by Hans is available for download.

Good implementation and fast speed do matter greatly for business users. ]

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Recently a post from Tableau Zen Master Alexander Mou showed up in my timeline on LinkedIn. The post was about Simple calculations for YTD/YoY and other timeframes in Tableau and he ended the post with an invite to comment.

I was asked a question: How to find out the IDs that showed up consecutively 5 times during the last 14 days?

How would you solve it?

Here I came up with 2 solutions. The 2nd one is a little simpler. Note that in either solution, we need to Show Missing Dates to make the calculations be based on contiguous dates. BTW, the last 14 days is irrelevant to the solution.

1. Solution with Running Sum

The idea is, CountD per Day for each ID equals 1 if it shows up, 0 if it doesn't.