Not necessarily, although it's a good stab at it. t = Take, which is basically your winnings minus your cost, which could be positive even if you don't place in the money. If your tournament uses bounty chips, a player could have a positive take by busting out a bunch of other players, but still not place in the money.
(n-r+1) * if(pw > 0, 1, 0) is closer. The only drawback here might be how you define "in the money". If a player wins a prize that isn't based on rank (such as for a high-hand or as a bounty on another player), their prize winnings will be positive, even though this might not qualify as "in the money" - depending on your definition.