SwissMicros Calculator Forum

Well, feel free to ask SM to change INTEG to use tanh-sinh quadrature, or whichever algorithm it is you prefer.
I know I'm not going to.

The integrator can be slow to converge, and using the solver on such an integral is going to be even slower, obviously. I am aware of numerical integration algorithms that tend to converge faster than the one used in Free42, but I remain unconvinced that the speed improvement is worth the increased ...

The function contains a RND. That's the cause of your display mode sensitivity right there.

Apart from functions that display numbers or convert them to strings, the only functions whose behavior is influenced by the display mode are RND, TRUNC, and AMORT. Thanks, Thomas. Though what's the stop condition for the Solver unless it finds a root directly? I.e. if the last two approximations r...

Apart from functions that display numbers or convert them to strings, the only functions whose behavior is influenced by the display mode are RND, TRUNC, and AMORT.

Actually, FUNC makes sense in a 4STK environment but much less so in NSTK, except to make cleanup (and LASTX restore) unnecessary. True, but I implemented FUNC before the big stack. And then there's the combination of FUNC and LNSTK or L4STK, to allow 4-level and n-level code to interoperate. The w...

I am currently working on redesigning the behavior of FUNC. In its current incarnation, I think FUNC has two flaws: it's over-complicated internally, and it doesn't do a good job of protecting the caller's state in NSTK mode. In 4STK mode, I think the way FUNC currently works is fine. A function usi...

It's mentioned in the HP-42S manual, page 186, "How the Solver Works."

rudi wrote: ↑

Tue Mar 28, 2023 5:33 am

Why bother about the .END. in the first place?

It just makes things a lot easier, both in terms of the calculator's internals and in terms of the user interface, if it is enforced that there is always at least one program in memory. And that's what the .END. is for.

I don’t quit the CUSTOM menu. The calculator does. In fact, the real problem is that this menu is not an application menu. It’s a function menu. So when the user calls another menu (like CLEAR or CONVERT), the calculator goes back to NO menu instead of CUSTOM. The best way to implement permanent CU...