About RPN history

[salvomic]

The history of Home is stored in History, that of CAS in CAS, inside Memory panel.
As RPN appear to be independent of Home (Textbook or Algebraic), where is stored its history?

Salvo

[Voldemar]

In RPN mode You can press [Shift], [+](Ans), the last operands will appear.
If You take Ans command from Catalog (but You must delete brackets after Ans) or type Ans (case sensitive, ANS is invalid), then [Enter], the list of last operands will appear.

[salvomic]

(12-05-2017 01:57 PM)Voldemar Wrote:  In RPN mode You can press [Shift], [+](Ans), the last operands will appear.
If You take Ans command from Catalog (but You must delete brackets after Ans) or type Ans (case sensitive, ANS is invalid), then [Enter], the list of last operands will appear.

yes, thank you, but I mean: where is stored the whole history...
i.e: if you press shift-mem, you can see CAS and History with the whole history of Some and CAS, but nothing for the "screen" with every stacks in RPN...

[Voldemar]

(12-05-2017 02:20 PM)salvomic Wrote:  but I mean: where is stored the whole history...

I think, there is not the place where You can see whole history of RPN mode. You can fill a lot of stacks, but when You execute the operations, situation in stacks is changing and You can not see how looked stacks before operations. Only from last operation You can restore operands with [Shift], [+](Ans) or with Ans command.

[salvomic]

(12-05-2017 02:57 PM)Voldemar Wrote:  I think, there is not place when You can see whole history of RPN mode. You can fill a lot of stacks, but when You execute the operations, situation in stacks is changing and You can not see how looked stacks before operations. Only from last operation You can restore operands with [Shift], [+](Ans) or with Ans command.

Well, I thought it would were a sort of "screen" like CAS an History (for Home). If one switch from Textbook and RPN (or viceversa) the two histories are maintained (Home in History, RPN I don't know where) and recalled when the user looks for them.

Anyway, you are right: there are so many stacks and they are changing often.

[Voldemar]

If You fill some stacks in RPN mode and do nothing with stacks content, this content You can see in Memory (Shift, Mem) under History. And this RPN history is different than history from Textbook/Algebraic entry mode.

[salvomic]

(12-05-2017 03:15 PM)Voldemar Wrote:  If You fill some stacks in RPN mode and do nothing with stacks content, this content You can see in Memory (Shift, Mem) under History. And this RPN history is different than history from Textbook/Algebraic entry mode.

yes, however if you are in RPN you can see RPN history, but if you are in Textbook (Algebraic) you can see the relative history, not both, also if somewhere the other one is stored. There is no way to pass entries from one to another (like from and to CAS, via Menu).
Maybe the other "Home" is stored internally.

[Voldemar]

(12-05-2017 03:19 PM)salvomic Wrote:  There is no way to pass entries from one to another

Copy - Paste.

[salvomic]

(12-05-2017 03:25 PM)Voldemar Wrote:  

(12-05-2017 03:19 PM)salvomic Wrote:  There is no way to pass entries from one to another

Copy - Paste.

yeah

[Voldemar]

Just found an interesting usage of Ans() command in RPN mode.
For example, fill stacks with 5 Enter 6 Enter 7 Enter 8 Enter. Then, for example, type 3 Enter. Now stacks looks like this:
5: 5
4: 6
3: 7
2: 8
1: 3
Then take command Ans() and type in brackets 1 (command Ans will execute for content of stack 1).
Press Enter and content off stack 3 stay on stack 1. Now stacks looks like this:
5: 5
4: 6
3: 7
2: 8
1: 7
Ans(1) works, do not work Ans(2), Ans(3)...

[salvomic]

Strange... I saw Help for and() but it ...doesn't help much.
In Textbook Ans(n) returns the nth line (stack).
In CAS Ans(n) applies n to an expression in stack 1: i.e.
2. 456
1. x^2
INPUT Ans(4)
returns 16.

In RPN, as you said, Ans(1) returns stack 3. ???

[Didier Lachieze]

(12-05-2017 03:56 PM)Voldemar Wrote:  Ans(1) works, do not work Ans(2), Ans(3)...

In RPN mode you pass the number of parameters inside the brackets, so when you type Ans(1) you tell the Prime to take one value from the stack and pass it to Ans.
If you type Ans(2) you tell the Prime to take 2 values from the stack levels 1 and 2 and pass them to Ans, which is not supporting multiple parameters....

in summary, in RPN mode you have:
Ans -> return the last values, for ex. 5 ENTER 6 x Ans returns 5 and 6 to the stack.
Ans(1) -> consume the stack level 1 and use it as index to return the value in the corresponding stack level

[Voldemar]

Help (User guide and onboard help) is good for Textbook/Algebraic mode. There is not enogh for RPN mode. Using the Prime in RPN mode requires some HP 50g (for example) experience.

[salvomic]

(12-05-2017 04:25 PM)Voldemar Wrote:  Help (User guide and onboard help) is good for Textbook/Algebraic mode. There is not enogh for RPN mode. Using the Prime in RPN mode requires some HP 50g (for example) experience.

I know it, in fact.

[Voldemar]

(12-05-2017 04:19 PM)Didier Lachieze Wrote:  Ans -> return the last values, for ex. 5 ENTER 6 x Ans returns 5 and 6 to the stack.

Ans on entry line then Enter returns {5, 6} to the stack. Last operands in list.
Only keypresses Shift, Ans returns 5 and 6. Five to stack two and six to stack one.
2: 5
1: 6

[salvomic]

About the stacks, they could also be named as X, Y, Z, T, ...
Like:
...
7.
6.
5.
T.
Z.
Y.
X.
As in the HP RPN heritage

[Voldemar]

(12-05-2017 04:40 PM)salvomic Wrote:  As in the HP RPN heritage

I do not know. Stack registers X, Y, Z, T is good, for example, on HP 35s, Roll down, Roll up... Last X are obvious, easy to keep in mind contents of registers. Stack levels on the Prime is like on the HP 50g. It is OK. The only remarkable difference - HP 50g has unlimited stack, Prime has 128 level stack. Is there someone, for whom it is not enogh?

[salvomic]

(12-05-2017 05:49 PM)Voldemar Wrote:  Stack registers X, Y, Z, T is good, for example, on HP 35s, Roll down, Roll up... Last X are obvious, easy to keep in mind contents of registers. ...

Also in HP 42s and others, and they will be X,Y,Z,T also in the next DM42 (see here)...

Four stacks are enough for general purpose, but 128 are better

[Voldemar]

(12-05-2017 05:56 PM)salvomic Wrote:  but 128 are better

Not in all cases.
Try this:
((((2*3+4)*2+5)*2+6)*2+7)*2+8=
On HP 35s
2 Enter Enter Enter 3 * 4 + * 5 + * 6 + * 7 + * 8 +
20 keystrokes.
On HP Prime
2 Enter Enter Enter 3 * 4 + * 5 + * 6 + 2 * 7 + 2 * 8 +
22 keystrokes.
or
2 Enter Enter Enter Enter Enter 3 * 4 + * 5 + * 6 + * 7 + * 8 +
22 keystrokes.

[salvomic]

too loooooooong :-D

2 keystrokes more than an old HP calc, hi!

The Prime, like HP 50g and other HP machines offer both RPN and ALG input: everyone can choose his way, and it sounds good

Only I would like to know where the RPN list is stored when we are used Textbook and viceversa...