Does anyone have the definitive formulae behind the excel PMT, IMPT and PPMT functions?
I've found very few but varying examples across the web.
I've looked these up, as needed, and implemeted them myself in a simple micro-service.
IRR, for example, though not specifically requested by you (shown in the top example below) was straightforward to implement. If you set up a micro-service, you can call that code with a single INSERT FROM URL line of code.
The beauty of a micro-service is that it works anywhere, with any operating system, on any computer, at any location, with virtually unlimited users. All for free. A micro-service is NOT a plug-in, so ....FileMaker or no FileMaker....a micro-service is totally independent so you can use it with any HTTP-enabled application (an application that can issue HTTP verbs like GET, POST, etc. Terminal, Browser? No problem.). What's not to love?! You Control The Code! (not some third party).
Check out my two micro-service tutorials in the App Innovations Area:
Create Micro-Services Using Java and the Spark Java Framework
The Simplest Micro-Service! (Python and Flask)
BTW, I'd be more than happy to help you get these functions working in your micro-service (that you could also then use from any other HTTP-enabled application, like the Browser, not just FMP).
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