I tried solving a long formula with four calculators (DM42, TI Nspire CX-II CAS, HP 40gs, EL-9950)

This is a comparison of four calculators solving the aspect ratio of the flag of Nepal. I used four calculators: the SwissMicros DM42, the Texas Instruments TI Nspire CX-II CAS, the Hewlett-Packard HP 40gs, and the SHARP EL-9950. The time it took for me to input the equation without practicing is also recorded and compared.

[@familiarshadow1]

I didn't realize that extended stack was an option now. I'm going to go update my DM42!

[@KYLXBN]

It's a very nice feature since I'm personally more used to RPL style instead of RPN!

[@cret859]

Nice idea. Speed formulea evaluation is a great challenge ! Only missing the HP Prime. I was just above 2 min (personal record time was 1'54") using textbook algebraic entry (and a bit helps of the COPY/PASTE facility) to get the result. But, my preferred horse is the HP-15C (personal time was 1'34"). As the DM 42C, this is pure RPN notation limited to 4 registers stack depth. Fortunately, register arithmetic and especially recall arithmetic spare a lot of stack space, keystrokes and time. One hit: start RPN computation on HP-15C by storing √2 into register R2, so the numerous (a-b√2) expressions are shorten to a [ENTER^] b [RCL][ × ][ 2 ][ - ] ! Storing repeating portions of the expression is also useful to spare keystrokes, stack space and time.

[@aab-el9bd]

but why not create a program that multiples by sqrt 2, and leaves the result in the stack?

[@christophe3d]

Challenge accepted. 1:20 on a DM42 with DB48X here: kzbin.info/www/bejne/r5-8eJucg813fbs.

[@R.B.]

RPN 48GX will beat out any algebraic CAS.

[@viscourtroy]

When I am watching the DM42 input, I want to cry that this is too hard to input... I am not used to this classic sci-calculator....

[@viscourtroy]

maybe TI series sci-calculators are good for inputting the complicated data....

[@martinkonz3495]

why is there no sound or any conclusion?

[@pasan.]

Dont think the 40gs got a fair go. I would have attempted this in CAS mode in th HP 40gs. It would have been much easier. With automatic bracket encasing you wouldn't need to keep track of brackets.

[@KYLXBN]

To be honest, I didn't think of that, so you may be right. But I'm afraid that the equation editor even in CAS mode would be able to handle such a long equation... it might just bail out before executing the entire equation.

[@christophe3d]

@@KYLXBN I tried that on an HP50G and HP48SX, both handle it with relative ease, though on the HP48SX, you have to be patient.

[@rowanmoorman7105]

Can you show me how to get the extended stack on the DM42?

[@scottcollins7513]

Very curious how you get the RPL unlimited stack on the DM42. Mine does not have that ability. Was there an update than enabled this? I’d love to have that ability - it’s definitely something I miss, having used the hp 28S and 48GX in the past. Thanks!

[@scottcollins7513]

I found the answer. As of version 3.0 of Free42, a “big stack” option is available. The downside is that programs designed for traditional 4-level stack may not work correctly.

[@KYLXBN]

Hi, sorry for the late reply; yes, it's a new feature on the latest software versions. I personally prefer RPL style, too, so it's an awesome feature!

[@odarge]

@@scottcollins7513 indeed . I do not activate this big stack option for this reason. Have a look on the new project of Thomas Okken , Plus42: an upgraded free42 with Units (like hp 48), directories, formulas/equation editor like on the HP 27s. Soon in a non free app (about 10€ I think).

[@scottcollins7513]

@@odarge Good info. Thank you. Calculators are sort of like cars where you would like to take the seats from this one, the engine from that one, the steering feel from another, etc., etc.

[@SteveSim99]

I tried entering this equation on my Casio fx-CG50 color graphing calculator. It was easy to enter the equation and thanks to the color matched parenthesis, it was also easy to keep track of the opening and closing parenthesis. Unfortunately when I press EXE, I received a "Stack Error" message. It turns out the equation was simply too complex for the fx-CG50 :(

[@hiroprotagonist8937]

Hi SteveSim99, I just tried with my CG50 and it can handle the equation with no issues, maybe you entered the parenthesis wrong as it happened to me twice and got that syntax error message. BTW, the result on my CG50 is 0.8203375878. Cheers!

[@Buddlertom]

Why didn't you use the HP like the DM? Using RPN instead of parenthesis. Both function the same way.

[@KYLXBN]

Unfortunately, the HP 40gs does not support RPN input.

[@dgm2006]

The Casio Classwiz can do this with 48 keystrokes to spare, and it’s only about $20.

[@chas2077]

Absolutely. I just did this with ease on the superb fx-991EX and with slightly fewer keystrokes than even on the mighty HP Prime! Much easier and with less lilelyhood of error than any of the calculators featured in this video.

[@aab-el9bd]

video?

[@aab-el9bd]

@@chas2077 Not likely. Video or it didn't happen.

[@carloscm1323]

Siento que lo haces muy lento, aun usando el RPN con la DM42, pero aun así, es lo mejor opción para ese tipo de fórmulas.

[@KYLXBN]

¡Hola! Sí, no es exactamente fácil convertir ecuaciones a notación RPN, así que estaba escribiendo un poco lento. El Nspire CX II es más fácil, pero un poco más lento, en mi opinión.