If only 1 more function…

[lrdheat]

Several HP’s left me wishing that they had just 1 more function…the 42S would benefit from XROOT(Y), the 35S with d/dx. That said, I very much like both. The 42S with a good amount of program space, nice handling of matrices and complex numbers, up to 6 letter labeling of variables, a decent statistics analysis capability. I like how the 42S can deal with undefined endpoints in an integral with a defined result. d/dx would have been nice, but a simple d/dx program is quite satisfactory for this. Perfect size for shirt pocket.

The 35S has the XROOT(Y)…d/dx would have made it easy to find the extremum of a function in the solve application. I like how the 35S will make a fraction conversion based on the fix setting of #digits to display. CASIO’s, TI’s will not find a candidate fraction if the decimal approximation does not agree with a candidate fraction out to at least 10 digits. I like how both the 35S and 42S allow the operator to choose the proper balance between digits displayed and accuracy/time to perform an integration. I will have to think about writing a d/dx program, perhaps one for algebraic and one for RPN.

[Dave Britten]

If I could add one function to the 42S, it would probably be RTN+1, i.e. return and skip the next step to allow for making programs/functions that can act like conditional tests.

Pushing and popping the entire stack to a background storage location in order to allow for easier recursion would also be nice, but that would be more than one function.

[Artur - Brasil]

I would add to HP-41CX or X-Function module one function to return the name of current X-File. So obvius...

[PedroLeiva]

As a HP 35s owner I would like to test a d/dx program, mostly for RPN system. Thanks in advance. Pedro

[Roberto Volpi]

And what about a LASTy command?

After an operator involving stacks x and y we see how useful LASTx can be, and a LASTy could be of great help too.

[brouhaha]

(01-25-2023 05:10 AM)Roberto Volpi Wrote:  And what about a LASTy command?
After an operator involving stacks x and y we see how useful LASTx can be, and a LASTy could be of great help too.

That sounds reasonable, but I suspect I'd get little use of it.

Do other people use LASTx a lot? I only use it when I'm seriously optimizing a program. I almost never use it outside a program.

[Steve Simpkin]

(01-25-2023 06:14 AM)brouhaha Wrote:  ...
Do other people use LASTx a lot? I only use it when I'm seriously optimizing a program. I almost never use it outside a program.

I only really used it occasionally to recover from mistakes.
From the HP-25 User's Handbook:
   

[Thomas Klemm]

(01-24-2023 09:12 PM)PedroLeiva Wrote:  As a HP 35s owner I would like to test a d/dx program, mostly for RPN system.

If you are okay with the crippled support of complex operations of the HP-35S you could use the Complex-Step Derivative Approximation.

Interestingly lrdheat already posted in the same thread:

(08-25-2018 05:19 PM)lrdheat Wrote:  This is why, if just 1 function could be added to the HP 42S, I would choose xROOTy !

[Dave Britten]

Oh, thought of another one: The HP 55 really needs a percent-change function like most other HPs have. I use my 55 as my general-purpose desk calculator, and that's the one thing that annoys me about it!

[Maximilian Hohmann]

Hello!

(01-26-2023 02:36 PM)Dave Britten Wrote:  Oh, thought of another one: The HP 55 really needs a percent-change function like most other HPs have.

That must be one of the functions that I have never used in any calculator, not even out of curiosity ;-)

My most missed function in any calculator (apart from a few like the HP-67) is "H.MS+". Ideally unshifted, because this is the only function I ever need calculator for.

Regards
Max

[ThomasF]

... if I could wish, I would have opted for a "LastXeq" function, ie a key that repeated the last executed command (ie. "last-not-on-keyboard-command").
By keeping XEQ key pressed, it could change from "XEQ __" to suggest the last executed command, or NULL if hold even longer.

I sometimes find myself executing a function a couple of times in a row, but to few to bother to assign it to a key ...

Cheers,
Thomas

[Gjermund Skailand]

...if I could wish, an elementwise multiplication for vectors and matrix on hp42 / DM42
best regards
Gjermund