on the RPN mentioning sharp pc-1211, v.albillo, el-506w and recurring topics

[pier4r]

So recap (for my perspective)

RPN:
- likely easier: to develop parsers for the calculator because the human does most of the work.
- possibly easier: to control if the typing went awry and one has to redo the computations done until then. (here a sort of history of what one typed won't be bad. Aside from the short one present on the 50g)
- likely easier: to match the RPN procedure with how we would proceed to compute a formula in our brain.
- likely: it forces you to think about the formula and elaborate it, instead of brainlessly type in the calc. (this may be a unwanted overhead sometimes)
- possible advantage (weak?): saves some keystrokes most of the time.
- likely easier: explore formulas and computation instead of copying them from paper/textbook.

algebraic:
- likely harder: if one cannot see the formula typed up to that point, it can be very frustrating if one makes a typo or has a doubt about a typo. Type everything again, no chances to inspect the formula mid course.
- likely easier: if one can see the formula that is typing. Since we are used to the algebraic notation.
- likely easier: to fix a formula if one can edit the formula that is typing.
- likely easier: if one can recall previous computations in form of algebraic entries.



As personal experience I generated randomly a formula (assuming no semplification).

\[ \frac{57^{6}}{22 \cdot 24} - \sqrt{ 53+81 } - \frac{ 25 - 7 \cdot \sqrt{92 \cdot 82} }{4^{2} \cdot 13 \cdot 81 } \]


and then I used:
free42 (rpn)
ti 34 (algebraic with no formula editing)
sharp el 506w (algebraic with formula editing and history)

with free42 those were 30 keystrokes. Counting numbers as 1, operations as 1, change of sign as 1.
with the ti34 and the sharp I used 40 keystrokes or slightly more.

The 'worst' feeling was on the ti34, because I was always in doubt whether I typed correctly the entries or if I missed the parentheses. Quite frustrating. I typed the formula actually three times to be sure of the result. (I did not type it on other systems before)

The free42 worked in one go. I did it again and I pressed a wrong function, and there was no undo (not that I know at least). That was frustrating.

The easier one, in terms of confidence or frustration level, was the 506w with the possibility to review the formula. Although the 506w gets ugly when one has long nested parentheses like (25-7* sqrt(92*82)) or long parentheses between operators; such as numerator/denominator of the last term of the formula.

Assuming that one value in the formula has to change (for whatever reason), with the free42 and the ti34 I need to retype everything again.

With the 506w it is just "up" to recall the last formula, editing the wanted part, and that's it.

That confirms my (biased?) view, that in terms of frustration having the ability to review and edit a formula is a big deal.