Hi,
I would like to be able to write column formulae which can perform various column formula functions within groups defined by rows in, for example, a column called 'group'. There are various mentions of the 'group by' button when using gemini, but I cannot find this.
For example, I would like to calculate the first cycle in the below table when the retention first passes 60 % (cycle where retention <= 60 %) for each group, A, B, and C.
How can I go about doing this? Thanks for the help 
My JMP version is JMP18 .
