WP43 News

This area is for discussion about these families of custom high-end Scientific Calculator applications for SwissMicros devices.
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Walter
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Re: 43S News

Post by Walter »

What is our rational display mode meant to be good for? For entry and output of rational numbers - think of our friends measuring timber in inches and fractions of them like 5 1/8 etc. You can find 1/64 for other material. And where rational (reasonable) people are happy with a decimal result they may want to find the next rational (fractional) number to deal with.

We don't do exact rational math - instead we do real math and convert to rational output within the boundary conditions given by you via DENMAX, DENANY, and DENFIX. Hence we display a rational output together with the indication whether this rounded output is greater, exactly equal, or less than the (underlying, hidden) real result. This notation was and is perfectly understood by the customers of our WP 34S since 2011. It is a rational display mode, nothing more.

Some nitpicky remarks:
  • Indications like ≤ or ≥ including equality are of little use.
  • In principle, an elevated [+] instead of [>] and [-] instead of [<] can be displayed as well. I don't see an advantage for either notation besides [>] and [<] being introduced 11 years ago.
WP43 SN00000, 34S, and 31S for obvious reasons; HP-35, 45, ..., 35S, 15CE, DM16L S/N# 00093, DM42β SN:00041
Bill K. - USA
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Re: 43S News

Post by Bill K. - USA »

When ">" is used monadically, it's placed before the value: "> 5", and everyone knows that whatever value we're talking about is greater than 5.

When ">" is used dyadically, it is placed between the values: "7 > 5", and here also its meaning is perfectly understood.

The problem is that the WP43S uses ">" in a nonstandard way: it places the ">" after the value, which isn't standard mathematical notation. The idea, I think, is that "7/5 >" is meant to be shorthand for "7/5 > x-register value".

But that's not what my mind naturally thinks. For the calculator--in all other circumstances--displays the value of the x-register: that is, that the value of x-register is equal to "7/5 >".

My natural impulse is to think that, by this reverse-order monadic notation, the WP43S is saying "7/5 (>)", e.g., that the value of the x-register is close to 7/5, but a little greater than that. But I'm wrong if I think that. Because what the WP43S means to be saying is that the x-register is close to 7/5, but is a little less than that.

Because of this confusion, I'd prefer "< 7/5" or "7/5\(^{-}\)", either of which IMO is less ambiguous and follows standard mathematical monadic notation.

Or we could bag the whole greater-than/lesser-than thing altogether, and instead display "7/5" when the value is exact and display "≈ 7/5" when it isn't. That is, FBR 2248.

(I'll now let this matter drop, for I think I've said everything I can say.)
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Re: 43S News

Post by H2X »

Bill K. - USA wrote:
Tue Jun 28, 2022 3:52 pm
I'd prefer "< 7/5" or "7/5 \(^{-}\)", either of which IMO is less ambiguous and follows standard mathematical monadic notation.
FWIW, this is how my brain works as well (when it works, that is...), and I think alignment with spoken language ("less than 7/5") really does help. Superscript plus or minus sign is fine with me also, for the same reason rudi mentioned (limits).

Oops, the formatting didn't seem to like being quoted. How it looks in Bill's original post is of course what my brain agrees with.
What is the metric tensor in imperial units?
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Walter
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Re: 43S News

Post by Walter »

Depends.
  1. If you want to tell that the displayed fraction (e.g. 7/5) is greater than the underlying real number (1.382) then you display 7/5 >.
  2. If you want to tell that the underlying real number is less than the displayed fraction then you display < 7/5.
Not really a difference - you can always swap equations. Though remember you don't see the real number in this display mode.

(Pssst: we could as well display 7/5 >x or x< 7/5. But don't you tell it to anybody!)
WP43 SN00000, 34S, and 31S for obvious reasons; HP-35, 45, ..., 35S, 15CE, DM16L S/N# 00093, DM42β SN:00041
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Over_score
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Re: 43S News

Post by Over_score »

Walter wrote:
Tue Jun 28, 2022 6:12 pm
(Pssst: we could as well display 7/5 >x or x< 7/5. But don't you tell it to anybody!)
My preference by far is displaying:
z = 5/2
y > 13/11
x < 7/5
DM42 SN00284 & SN03835 running C47, HP34C, HP41CV, HP42S, HP35s, WP34S, HP Prime
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Walter
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Re: 43S News

Post by Walter »

Then I vote for applying this to > and < only - I 'd avoid putting bells and whistles to the equalities.
WP43 SN00000, 34S, and 31S for obvious reasons; HP-35, 45, ..., 35S, 15CE, DM16L S/N# 00093, DM42β SN:00041
Bill K. - USA
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Re: 43S News

Post by Bill K. - USA »

I've been reading the WP43S Owner's Manual and I noticed several comments directed at the people of the United States regarding our units of measurement (pp. 14, 20, 93, 112, 136, 290), our NASA Mars probe failure (p. 33), our laws requiring warnings (pp. 14, 15), our responsibility to the Bikini Atoll (p. 99), our guns (p. 107), and our elected leaders (p. 136). I appreciate that the manual is attempting to have a lighter tone, but the comments feel a bit pointed

So I ask if maybe the writers could mix in a little praise for the U.S. while they're at it (like crediting the U.S. with the lunar landings on p. 18, or by pointing out that HP was a company birthed in America, etc.). Or maybe they could include a similar number of self-deprecating comments regarding their own countries. Or maybe simply cut back some on the critique. After all, when everything is said and done, it's an owner's manual for a scientific calculator, and that for a calculator which, presumably, many Americans will also wish to use.
Last edited by Bill K. - USA on Thu May 04, 2023 10:40 pm, edited 6 times in total.
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inautilus
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Re: 43S News

Post by inautilus »

Bill K. - USA wrote:
Sat Jul 02, 2022 12:07 am
I've been reading [...] After all, when everything is said and done, it's an owner's manual for a scientific calculator, and that for a calculator which, presumably, many Americans will also wish to use.
+1
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Walter
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Re: 43S News

Post by Walter »

About fractions, a.k.a. rational numbers:

How about implementing a rational display mode like this:
fractions.JPG
fractions.JPG (19.29 KiB) Viewed 1296 times
.
The relation is always located at the same position. For the other displayable stack registers, y, z, or t will be shown instead of x if applicable. For a fraction being exactly equal to the real number 'under the hood', no additional indication is required (if it's neither > nor < it must be equal) - this keeps the fraction display clean.
WP43 SN00000, 34S, and 31S for obvious reasons; HP-35, 45, ..., 35S, 15CE, DM16L S/N# 00093, DM42β SN:00041
H2X
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Re: 43S News

Post by H2X »

Walter wrote:
Mon Jul 04, 2022 10:19 pm
How about implementing a rational display mode like this [...]
Looks like inequalities to me, because of the x. But I get that you want to name the register.

I am with Over_score, though, I like the register reference furthest to the left.
What is the metric tensor in imperial units?
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