
1. Re: How do you create a calculated field to represent in graph the gap between 2 means?
Dimitri.B Feb 23, 2012 3:53 PM (in response to sophiegaudet)The approach will largely depends on how your data is structured. Can you share a sample?

2. Re: How do you create a calculated field to represent in graph the gap between 2 means?
sophiegaudet Feb 24, 2012 7:46 AM (in response to Dimitri.B)Here is a sample. The data are survey responses on a scale of 15. I simply would like to add either a sheet or addition to the graph that is a calculation of the mean for A1a. minus A2a. (and so forth for each item).

Trail.twbx.zip 41.9 KB


3. Re: How do you create a calculated field to represent in graph the gap between 2 means?
Dimitri.B Feb 26, 2012 7:27 PM (in response to sophiegaudet)With the data as in your sample, just create a custom calculation like:
AVG([A1A])AVG([A1B])
You will need to repeat this to create similar calculations for every pair of scores that you want to compare (see attached for an example).
If you reshape (unpivot) the same data using Tableau data reshape Excel addin, then you will only need one table calculation, and you can even use parameters to compare with every score. There are also other benefits in using this approach, see unpivoted examples in the attached workbook.
Table calculations are more complicated than the ordinary ones, but in return they can do a lot more.

Trail (mod).twbx.zip 166.1 KB


4. Re: How do you create a calculated field to represent in graph the gap between 2 means?
sophiegaudet Mar 8, 2012 12:51 PM (in response to Dimitri.B)Thanks. Greatly appreciated. What would be great would be a course on representing survey data.