I'm trying to show an average of the last 30 days work of data. I can't get it to work in Text and Image.
In a table, here's what I have:
rangeavg(top([my_field], 1, 30)
This shows my data in the table OK and calculates the correct average.
But I don't want this in a table, I want it in a Text & Image box. But when I put the same expression in Text & Image, I get a null output. My guess is that this has something to do with sorting. Of course, the documentation is of no help whatsoever.
The only other way I can think of doing this is to use firstsortedvalue 30 times, but this seems to be an awful solution. I thought of using a set expression, but I can't for the life of me work out what the set expression would be.
My underlying data is in this form:
Date, my_field
