Troubleshoot your calculations by creating a Tableau troubleshooting view! Read the first post in this series to get an overview of the method.

 

As you troubleshoot your calculation, it is important to verify that the values in the view are correct. Both to help us continuously focus in on the issue, and to build an understanding of what is actually happening.

 

Ask guiding questions

  1. Are these values correct?
  2. How are these values actually generated?
  3. How do I calculate my end-goal?

 

why: Anytime you feel stuck, ask these questions to will help expose missing information you still need to troubleshoot the calculation. As you move through your investigation, the answers to these questions should become more and more specific until they sound like math problems. Formulating answers as math problems makes it easier to translate what you want Tableau to do into calculation syntax.

 

For example, if you were troubleshooting a quick table calculation to find the percent of total poker players in each game in a tournament, you may answer #3 as: “The percent of total should be the players in an game out of the players in the tournament

 

But eventually you could add more information to your answer until it sounded like: “The percent of total should be the unique count of players in an event, which is 4 for the first event, divided by the sums of all unique player counts for all events in the tournament, which is 4+5+3+6+5+4+2=29.” Of course I am making up numbers here, but these would be numbers from your view.

 

Add totals and subtotals with Total using Sum

  1. Navigate to Analysis > Totals > {Select an option}
  2. Right-click the measure field in the view
  3. Select Total using > Sum

why: Tableau Desktop can do the math for you, but Automatic totals are not always the sum of the values in the view. See Grand totals and aggregations to learn more about Automatic totals

 

Add more decimal points

  1. Right-click the measure field in the view
  2. Select Format...
  3. In the right-hand Format pane, under Default open the Numbers dropdown menu
  4. Select Number (custom)
  5. Adjust to the number of desired decimal places

why: Sometimes values appear wrong due to rounding errors. For example, percentages formatted as normal numbers without decimals will appear as 0 or 1 due to rounding.

 

Reveal hidden data

  1. Navigate to Analysis > Reveal Hidden Data

why: There is no visual indicator that data has been hidden, but sometimes hidden data is the cause of the issue.

 

Show headers

  1. Right-click the dimension field in the view
  2. Check Show Header

why: Headers may have been turned off in the final view, but will help us track data when troubleshooting

 

Check footer summary information

  1. Check the number of marks, number of rows, number of columns, and/or the sum of all measures in the bottom bar

why: This is a quick way to get some additional information about the view

 

Check tooltip summary information

  1. Click a header in the view
  2. Check the number of items selected and/or the sum of all selected measures

why: This is a quick way to count marks in a partition in the view. Remember that this will count all marks, which is rows x columns.

 

Next time we will look more in-depth at special cases, like Automatic grand total. To see it all in action, check the Calculations Survival Guide session at Tableau Conference!