HP 50g Solve Equation Command

[Josiah]

I have looked through the AUR, UG, and the web and have been unable to
find a command for the built in solver that I can reach by keying RS
NUM.SLV and selecting "1. Solve equation". I find that solver useful
for the type of equations that I am solving because I can see if I am
still missing a value for more than one variable in the equation. Is
there a command to reach this without keying it in manually?

Thanks in advance,
Josiah

[Andreas Möller]

Hello,

only via LIBEVAL.

If you want to use the *full* screen with the numerical solver (and
different fonts, etc., etc.) and a GUI for the MES then consider my
commercial replacement for the GUI.

Details can be found on my website
http://www.software49g.gmxhome.de

Regards,
Andreas

[Nate]

You can enter # B4001h LIBEVAL
If you'd like you can creata a small program << # B4001h LIBEVAL >>
and assign it to a key in user mode.

I have a small program labelled EQSLV that will take the equation on
the stack, assign it to the EQ variable, switch to a temporary
directory, open the Equation Solver, and then switch back to whatever
directory I was in when the program was evaluated. I don't like to
clutter whatever directory I'm in with variables created by the
solver.

<< PATH -> Pth << TEMP STEQ # B4001h LIBEVAL Pth EVAL >> >>

Pth is a local variable that stores the current directory
TEMP is the name of a directory I have 'hidden'

[John H Meyers]

On 10/25/2011 3:50 PM, Josiah wrote:

> I have looked through the AUR, UG, and the web and have been unable to
> find a command for the built in solver that I can reach by keying RS
> NUM.SLV and selecting "1. Solve equation"

> Is there a command to reach this without keying it in manually?

Can be stored as a named program
(then press its key to run it):

\<< #B4001h LIBEVAL \>> 'NSLV' STO

The original menu-based version of the same solver
can be invoked via 30 MENU
after the "equation" is stored in 'EQ'

Example: 'Y=X^2-5*X+6' STEQ 30 MENU

Right-shift then cursor-down
reveals which variables are undefined,
as well as the values of all currently defined variables.

In many cases, the menu-based solver
may require fewer key presses to use,
since a single keypress (on a menu key)
stores a stack value into any variable;
to solve for any variable, right-shift then press its key
(left-shift recalls values to the stack).

Note that there is no need to press CALC
(as the screen form requires)
to calculate "on the side," because the stack
is always available when using the menu-based solver.

Note also that this entire solver is _in the menu itself_
(the menu and its key definitions do all the work!)

Various other very useful functions of the original HP48 series
are also still in the HP49/50 series, buried and forgotten,
even though they may actually be easier and more efficient to use
than their later "form-based" counterparts.

Other areas of knowledge have also fallen away in "modern
civilization," yet the experience of some gems of forgotten values
often reveals that recent developments are not necessarily the best.

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[John H Meyers]

On 10/25/2011 8:46 PM, John H Meyers wrote:

[re menu-based numeric solver: 30 MENU ]

> Right-shift then cursor-down
> reveals which variables are undefined,
> as well as the values of all currently defined variables.
>
> In many cases, the menu-based solver
> may require fewer key presses to use,
> since a single keypress (on a menu key)
> stores a stack value into any variable;

> to solve for any variable, LEFT-shift then press its key
> (RIGHT-shift recalls values to the stack).

Sorry, I must have been standing on my head,
and had originally mixed up "right" and "left" ;-)

--

[Josiah]

> Various other very useful functions of the original HP48 series
> are also still in the HP49/50 series, buried and forgotten,
> even though they may actually be easier and more efficient to use
> than their later "form-based" counterparts.

John,

Thanks for the information on the menu based solver. I have put it in
my main custom menu so it is always handy and I don't even use the
form based solver. Being able to use the stack to perform
calculations is really handy. Is there somewhere I can go to find
more shortcuts like this one? I have read a lot in the manuals and
never came across any reference to the menu based solver.

Thanks everybody else for their input. This forum is really helpful.

Josiah

[John H Meyers]

On 11/03/2011 11:34 AM, Josiah wrote:

>> Various other very useful functions of the original HP48 series
>> are also still in the HP49/50 series, buried and forgotten,
>> even though they may actually be easier and more efficient to use
>> than their later "form-based" counterparts.

> Thanks for the information on the menu based solver. I have put it in
> my main custom menu so it is always handy and I don't even use the
> form based solver. Being able to use the stack to perform
> calculations is really handy. Is there somewhere I can go to find
> more shortcuts like this one? I have read a lot in the manuals and
> never came across any reference to the menu based solver.

Scanned versions of HP48G series manuals are downloadable;
the old "AUR" (mostly detailed UserRPL command specs)
is still basically intact within the more recent AUR,
but quite a bit of the old User's Guide has been forgotten,
and a number of original built-in menus, though still existing
and still possible to display via <menu number> MENU
are not even otherwise reachable via keyboard navigation
on the HP49/50 series.

Keyboard "POLAR" and "RAD" mode toggles also disappeared
in the series transition, as did a once-convenient keyboard "Angle symbol,"
the CAS having won a "turf war" over what engineers used to value :)

A couple of CAS menus even have indistinguishable menu keys, e.g.
you see two "SOLVE" in menu 120 -- which one is actually SOLVEVX ?
Any HP48G menu which might have been like this was made unambiguous,
e.g. in original menu 73.02 the DROPN menu label was shown as DRPN
so that you could not confuse it with DROP (a new font in HP49/50 series
now allows an extra character to be visible, so that's not necessary
in newer series menu 73.03) Some menus in the new series
were even alphabetized instead of having more functional grouping,
introducing little inefficiencies all over the place.

Hardware-wise, the early production runs of HP49G+ have keys
that tend to break off after a while -- it may be slower
to type on an emulator, but at least those keys never fall off :)

Despite its slower CPU speed, Raymond single-handedly
sees to the continuing improvement of the HP48 series, via SpeedUI :)

HP 48G Series User's Guide:
<http://www.hpcalc.org/details.php?id=3937>

HP 48G Series Advanced User's Reference Manual:
<http://www.hpcalc.org/details.php?id=6036>

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[Jacko]

Does using the other shift key on one of the menus near the cursor keys display the fully spelt out list like the 48GX? (I mean one without the both shift colours having a word)

[John H Meyers]

On 11/07/2011 1:59 AM, Jacko wrote:

> Does using the other shift key on one of the menus near the cursor keys

> display the fully spelled out list [of current menu keys] like the 48GX?

"Review": RightShift, CursorDown 48G/49G/50G

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