I guess can I ask you why would you not want to use this if it gives you what you want? I mean do you have an alternative way to do it? I know this can be done with The As-Of Table or something similar in the script, but do you have a better way to do this?
I'm sorry, I was just wondering what the differences between your first suggestion and second suggestion are. I didnt understand the avg(1). Thought I might learn a thing or two.
Without selection in Date field the result of the two expression will be the same. The difference arises when you select a single date or multiple dates. 1st expression will restart the accumulation based on selection, where as the 2nd expression will only show the dates you have selected, but will show accumulation from the beginning of time.
You can solve your problem without RangeSum function, for this you should do the following:
1. Create additional expression Sum(Sales)
2. Use Accumulation and Accumulate 3 Steps Back
After this you will get following result:
the 2nd expression is so cool ! it's really a smart use of Avg(1)
the only problem is , user can not order the table by Date desc , or order by sales volume right ?
is there any chance to fix this ? or we have to do it in Script ?