Currently, Tableau does not support sorting on table calculations. This is a good request to put under the Ideas section of Community.
My best suggestion would be to inform the user how to resort after changing the filter.
Sorry I don't have a copy of version 6 on this computer, but you can accomplish what you are looking for with a formula like:
THEN [Number of Records] END
))/TOTAL(SUM([Number of Records])))
and then placing it as the first pill on the Rows shelf as a discrete blue pill, and set its Compute using to "Region (group)". Additionally, you can hide the header for this pill, and adjust the format of the borders so it is invisible.
If you have version 7, you can see this done in the attached.
Maybe I'm not using standard approaches but the amount of times I read 'Tableau cannot do X or Y' is infuriating. It does sound like several key ones like filtering on secondary sources have been added in v8 though.
Any idea if sorting on table calcs has been added please? Thanks
I've got a bar chart that uses calculated fields in the row and column lines.
The bars and their colouring are currently all over the place as they're in alphabetical order
There's no option to sort these calculated fields
I'm on desktop v7.0
Having a bar chart ordered by size seems a fairly basic option to me - any ideas please?