Plus42 Equations, Preview Release

[Thomas Okken]

Yes, but Plus42 already has the TVM functions, I implemented them in the equation language. I just need to do some work to expose that functionality in the RPN environment.

The existing functions are a bit cumbersome in RPN mode, since they all take six parameters: the four knowns of N, I%YR, PV, PMT, and FV, and two additional parameters to specify begin/end mode and the number of payments per year. You need NSTK mode just to be able to push all those parameters onto the stack.

One option would be to simply create an equation like N=N(I%YR:‌PV:PMT:FV:P_YR:BEGIN), pass it to EQNSLV, and rely on the SOLVER menu and the direct solver's ability to directly solve this equation. But that seems a bit messy. If I can't get that to work the way I want, I'll just implement the desired functionality directly, which will mean more work to implement it, but should result in a cleaner user interface.