Last value in painless script

[martinsbleu]

Hello Team,

Like in the title, I am trying to get the last_value of a field for the Return On Investment calculation. Normally, I can do this in Lens Formula (rf. below) on a monthly index. But I don't know how for a daily index.

ROI = sum(*sessions*) / last_value(*subscription_fee*)

So the idea is to get the last subscription_fee, I've been trying to play around with @timestamp field but no hope.

How could I tackle that ?
Thanks in advance,

[Andrew_Tate (Drew Tate)]

Hi @martinsbleu !

A couple of questions:

1. the ROI formula is (current value - initial value) / initial value. Can you clarify how your data are supposed to fit that formula?

2. when you say

@martinsbleu

a daily index

do you mean that each document in the index represents the value of the investment on a particular day?

[martinsbleu]

Hello @Andrew_Tate !
Thanks you for reply!!

1. Yes, pardon me, current value would the total number of sessions (sessions field).
2. A daily index is an index with data populated each day. So I think it is close to what you have described (: