Conditional summation notation

Post date: 2020-08-01 11:00:48
Views: 490
I'm trying to show a summation for observations i to n, starting with i = 1, that is only applied when another variable (treatment) is equal to 0. What's the correct notation for that?

The idea that I'm trying to turn into mathematical notation is "Each control unit in a given stratum has an uncorrected weight equal to (the unit's survey weight divided by the sum of all survey weights of control units in that stratum) multiplied by (the sum of all survey weights of treatment units in that stratum)," if that helps for context. I feel very self-conscious asking this question; please be kind.
Number of Comments
Please click Here to read the full story.
 
Other Top and Latest Questions:
The SALT deduction limit is $40,400 for 2026. Here's how to maximize it
Levi Strauss hikes profit guidance after tariff refunds, but its sales outlook is less optimistic
SpaceX’s plans to buy more Nvidia GPUs is keeping Jim Cramer bullish on the chip stock
Microsoft to sell $2,599 Surface Laptop Ultra containing Nvidia AI chip
Thursday's big stock stories: What’s likely to move the market in the next trading session
Movie: Queen Margot
Stargate SG-1: Abyss Rewatch
Elon Musk blames Indian 'oligarchs' for stalling Starlink launch
TSMC September sales hit another record as AI boom rolls on
Oil gains as Middle East hostilities, potential escalation stoke supply worries