[TUHS] The most surprising Unix programs
gtaylor at tnetconsulting.net
Sat Mar 21 02:07:39 AEST 2020
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
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
> 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
For example, let's start with Pythagorean Theorem
a² + b² = c²
This is relatively easy to enter in infix notation on a typical
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.
[square root] # to solve for c
Conversely infix notation for comparison.
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
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
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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