[TUHS] The most surprising Unix programs
Grant Taylor
gtaylor at tnetconsulting.net
Sat Mar 21 02:07:39 AEST 2020
+COFF
On 3/20/20 8:03 AM, Noel Chiappa wrote:
> Maybe I'm being clueless/over-asking, but to me it's appalling that
> any college student (at least all who have _any_ math requirement at
> all; not sure how many that is) doesn't know how an RPN calculator
> works.
I'm sure that there are some people, maybe not the corpus you mention,
that have zero clue how an RPN calculator works. But I would expect
anybody with a little gumption to be able to poke a few buttons and
probably figure out the basic operation, or, ask if they are genuinely
confused.
> It's not exactly rocket science, and any reasonably intelligent
> high-schooler should get it extremely quickly; just tell them it's
> just a representational thing, number number operator instead of
> number operator number.
I agree that RPN is not rocket science. And for basic single operation
equations, I think that it's largely interchangeable with infix notation.
However, my experience is, as the number of operations goes up, RPN can
become more difficult to use. This is likely a mental shortcoming on my
part. But it is something that does take tractable mental effort for me
to do.
For example, let's start with Pythagorean Theorem
a² + b² = c²
This is relatively easy to enter in infix notation on a typical
scientific calculator.
However, I have to stop and think about how to enter this on an RPN
calculator. I'll take a swing at this, but I might get it wrong, and I
don't have anything handy to test at the moment.
[a] [enter]
[a] [enter]
[multiply]
[b] [enter]
[b] [enter]
[multiply]
[add]
[square root] # to solve for c
(12 keys)
Conversely infix notation for comparison.
[a]
[square]
[plus]
[b]
[square]
[square root]
(6 keys)
As I type this, I realize that I'm using higher order operations
(square) in infix than I am in RPN. But that probably speaks to my
ignorance of RPN.
I also realize that this equation does a poor job at demonstrating what
I'm trying to convey. — Or perhaps what I'm trying to convey is
incorrect. — I had to arrange sub-different parts of the equation so
that their results ended up together on the stack for them to be the
targets of the operation. I believe this (re)arrangement of the
equation is where most of my mental load / objection comes from with
RPN. I feel like I have to process the equation before I can tell the
calculator to compute the result for me. I don't feel like I have this
burden with infix notation.
Aside: I firmly believe that computers are supposed to do our bidding,
not the other way around. s/computers/calculators/
> I know it's not a key intellectual skill, but it does seem to me to
> be part of comon intellectual heritage that everyone should know,
> like musical scales or poetry rhyming. Have you ever considered
> taking two minutes (literally!) to cover it briefly, just 'someone
> tried to borrow my RPN calculator, here's the basic idea of how they
> work'?
I'm confident that 80% of people, more of the corpus you describe, could
use an RPN calculator to do simple equations. But I would not be
surprised if many found that the re-arrangement of equations to being
RPN friendly would simply forego the RPN calculator for simpler
arithmetic operations.
I think some of it is a mental question: Which has more mental load,
doing the annoying arithmetic or re-arranging to use RPN.
I believe that for the simpler of the arithmetic operations, RPN is
going to be more difficult.
All of this being said, I'd love to have someone lay out points and / or
counterpoints to my understanding.
--
Grant. . . .
unix || die
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