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Hello all.

One of the features I found quite helpful from my 48GX was the ability to edit a subexpression from the Equation Writer on the stack and when done, proceed back into the Equation Writer environment. Is that possible on the 50G?

Also, is there a way on the 50G to take an expression from the stack and:

if it's a matrix, edit that in the Matrix Writer or

if it's an equation, edit that in the Equation Writer?

Thanks for your advice.

Edited: 22 Apr 2012, 11:30 a.m.

Hello Matt !

1/ "One of the features I found quite helpful from my 48GX was the ability to edit a subexpression from the Equation Writer on the stack and when done, proceed back into the Equation Writer environment. Is that possible on the 50G?"

Just select the subexpression in eqw and clic softmenu EDIT. Then edit and when it is OK clic ENTER to proceed back EQW

2/ "Also, is there a way on the 50G to take an expression from the stack and: if it's a matrix, edit that in the Matrix Writer or if it's an equation, edit that in the Equation Writer?"

Just clic the down arrow.


Edited: 22 Apr 2012, 11:49 a.m.

Hi there. Just tried editing an equation with an equation in the stack but, the Equation Writer does not launch. Instead, it just allows me to edit in the command line. Am I missing a step or need to set a system flag?

Edited: 22 Apr 2012, 12:31 p.m.

Hi.

Can you tell us which expression you are trying to edit and the keystroke sequence you are actually using to achieve it?

Cheers.

Luzi (Brazil)

Let's say, I'm editing a Square Root expression. So level 1 of the stack looks like: \/-(1-x^2)

The minute I press the down arrow, I get a blinking left arrow and the expression on the command line.

On the other hand, if I press F1, it recalls whatever variable, program, equation on Soft key 1 to the stack.

Hi.

Well, based on what you mention there is nothing wrong. I actually tried to think of a flag that might control this level of operation, but I did not even find any clue with the calculator itself.

I get what you describe if I press the up-arrow instead of the down-arrow: a command-line editing.

I have used the HP50G this way, and once you have an expression in stack level 1 (it must be surrounded by the algebraic identification, I mean, two ' ), pressing the down-arrow key 'invokes' the editor that fits best for the object in stack level 1.

I'll try to find something else.

Sorry not to help you the way you need now.

Luiz (Brazil)

Edited: 22 Apr 2012, 8:01 p.m.

Well, after fiddling around, I noticed something. Instead of ' (the single quote) surrounding the expression, there was a curled quote symbol. I'm not certain what data type is enclosed with a curled single quote but, that is what was getting in the way.

By the way, is there (in any of the 50G manuals) a listing of the data types and the delimiters they use?

Hi.

(added) The main delimiters for the HP50G are:

#  for binary integers
' for algebraic objects
" for strings
[] for matrices and vectors
{} for lists
«» for programs
_ for tags
If there is no delimiter, the calculator will evaluate the object.

There are some sources for additional information, the best ones deal with System RPL because knowing the object types in deep is demanding. The HP50G AURM (Advanced User's Reference Manual) surely lists them all (try page 3-262).

Cheers.

Luiz (Brazil)


Edited: 22 Apr 2012, 8:43 p.m.

Yes, they're listed but, no samples to see the delimiters they use.

You are probably seeing the ` ` delimiters I suspect. These essentially mean "evaluate the contents in the delimiter immediatelly" and are an essential part of how the algebraic mode was implemented on top of the RPN stack.

If I recall correctly, holding the shift key and pressing the tic with the shift held down generates that tic instead of the standard ''.

TW

Nope. I just tried the keystroke you suggested. What is actually there on the expression in question is a curved quotation mark surrounding the algebraic expression ("3/SQRT(1-x^2)"). There is no gap as there would be with single quote pressed twice.

Edited: 22 Apr 2012, 11:18 p.m.

If your equation looks like this:



then it is in a list and nothing will get the Equation Editor to edit it.


You have to get it out of the list with LIST-> to get it like this:




and then pressing the DOWN arrow will automatically edit it in Equation Editor.

Hi there.

Thanks all for your help. What I am seeing is not a list, not a program, not a vector, not a matrix. But, the delimiter I'm seeing is a curly quote (“3/SQRT(1-x^2)”). What data type is associated with these curled quote marks?

Edited: 23 Apr 2012, 2:55 p.m.

Can you post a screen shot?

Sorry, the list brackets were the only "curly" things I could think of. There is one other one I can think of:


This can also not be edited with the Equation Editor. By the way, this was entered in Algebraic Mode. (This inverse function equation cannot be entered in RPN mode, see my comments on it here: HP-50g bug - some inverse statistical formulas in RPN mode)

If you can't generate a screen shot, it might help if you can execute TYPE on the object and tell us what value it is?

...

I just realise that if you do :

[RightShift & EQW (clic EQW without releasing the RightShift)] instead of [RightShift (release the key) then EQW] you will get these characters (inversed ') instead of executing de EQW

hummm looks strange,i never noticed this before.

Edited: 23 Apr 2012, 5:19 p.m.

Hi all.

Thanks for all your time and effort. I'm going to see if it was some misstep on my part--system flag setting, mode switch or equation entry mishap.

But, I do recall, someone here mentioning that if the entry mode is 'Algebraic' and not RPN, that affects why the Equation Writer does not launch when the down arrow is pressed on an expressuin in Level 1. Right?

So, I'm just going to start all over again to see if the glitch happens again. If I get a quotation mark delimiter, I'll make several copies on the stack and put the thing in a variable. That way, I can get the TYPE and do whatever other techniques you suggested.

**UPDATE

I just tried my Equation Editor project again. This time, I see my equation in true form and when I press the down arrow, the Equation Writer launches allowing me to edit my equation.

Not certain what step I slipped on the last time. In any case, all is well and thanks for your very generous help.


Edited: 24 Apr 2012, 7:28 p.m.

How do I obtain a screen shot and transfer it to my computer?