0645: "RPS"

This forum is for the individual discussion thread that goes with each new comic.

Moderators: Moderators General, Prelates, Magistrates

Zylon
Posts: 142
Joined: Fri Jan 30, 2009 5:37 pm UTC

Re: "RPS" Discussion

Postby Zylon » Mon Oct 05, 2009 2:15 pm UTC

I must say, I'm honestly stunned how many people here didn't get such a simple reverse polish notation joke. It's not like RPN is particularly obscure. I'm terrible at math, have never used RPN, and haven't even thought about RPN in years, but I got the reference instantly. Sheesh.

That being said, my first thought on seeing the artwork, but before reading the caption, was "deconstructed hot dog". I blame Top Chef.

averageJon
Posts: 4
Joined: Mon Oct 05, 2009 2:14 pm UTC

Re: "RPS" Discussion

Postby averageJon » Mon Oct 05, 2009 2:16 pm UTC

Shouldn't it be bun, sausage, mustard? After all, the mustard is applied last.

Zylon
Posts: 142
Joined: Fri Jan 30, 2009 5:37 pm UTC

Re: "RPS" Discussion

Postby Zylon » Mon Oct 05, 2009 2:20 pm UTC

jc wrote:One of the fun way to debunk claims about rationality in The Market is that a number of usability studies have shown that nearly everybody (except the occasional math wiz) can use RPN calculators more easily than the infix kind. But almost all commercially available calculators use infix notation. This is just one of many examples showing that the commercial world isn't concerned with usability.

Or, the far more likely explanation that almost all calculators use infix notation because almost all PEOPLE use infix notation, and that you're a loony.

User avatar
cnaude
Posts: 1
Joined: Mon Oct 05, 2009 2:28 pm UTC

Re: "RPS" Discussion

Postby cnaude » Mon Oct 05, 2009 2:32 pm UTC

Two words come to mind: Hungarian Notation

Air Hadoken
Posts: 16
Joined: Wed Mar 18, 2009 8:25 pm UTC
Location: San Francisco, CA
Contact:

Re: "RPS" Discussion

Postby Air Hadoken » Mon Oct 05, 2009 3:06 pm UTC

I thought the comic was hilarious. This one is going up on my cubicle wall.

Good job, Randall.

User avatar
jc
Posts: 356
Joined: Fri May 04, 2007 5:48 pm UTC
Location: Waltham, Massachusetts, USA, Earth, Solar System, Milky Way Galaxy
Contact:

Re: "RPS" Discussion

Postby jc » Mon Oct 05, 2009 3:15 pm UTC

Zylon wrote:Or, the far more likely explanation that almost all calculators use infix notation because almost all PEOPLE use infix notation, and that you're a loony.


Nah; you got the history wrong. People were doing arithmetic long before there were any calculating machines (mechanical or electronic), and they used postfix to do it. Just think of how you do arithmetic on paper (if you ever learned that). You first write down the numbers, then you perform the operation, writing the result below the inputs. You don't write down one number, perform the operation, write the second number, then write the result, which is what you'd do if you were using infix notation. The order you do things (write numbers, perform operations) exactly matches RPN/postfix.

Similarly with most mechanical adders. (They generally didn't do multiplication.) You enter a number, then enter another number, pull the handle, and the sum appears. Infix notation appeared with the first electronic calculators, and it was an attempt to implement the usual printed (17+23) sort of notation. This was because the implementers had a lot of math training, and thought in infix notation, though they probably used postfix for doing arithmetic on paper.

Also, the early electronic calculators had limited memory, and infix required storing only three numbers, while postfix requires a stack of N>3 numbers, if it's to be useful. Figuring out an order of operations that would work with only 3 memory registers was left to the user.

But it doesn't take too much asking around to figure out that the real reason is that the designers of calculators have never much bothered with that fancy-schmancy "ergonomics" stuff. They just implement infix because "That's the way it's done", and don't give it any more thought. Customers "like" infix because that's the way they learned to use calculators. They don't notice that arithmetic on paper does it differently, because they don't think about such things at all. They just follow the first thing they were taught, and have no intention to ever learn anything else.

RPN calculators are mostly used by people who do a lot of arithmetic, and want a calculator that's easy to use. They tend to understand what they're doing, so they understand why postfix is better - i.e., simpler and faster - than infix, and are willing to spend some time and money to get a calculator that will save them time and effort in the long run.

Infix calculators are sorta like the qwerty keyboard. They were both bumbling first tries to make something work with the hardware limitations of the time. Subsequent designs just blindly followed precedent, because "That's how it's done", with nobody but a few geeks wanting to think about whether there might be a better way. A lot of our UI design is like this. Once a precedent exists, it can take centuries for a different design to succeed. Manufacturers know that better designs usually fail because, no matter how bad the current design, most people prefer it to learning something new. Especially if it has anything to do with that horrible math stuff.

Mihijo
Posts: 1
Joined: Mon Oct 05, 2009 3:37 pm UTC

Re: "RPS" Discussion

Postby Mihijo » Mon Oct 05, 2009 3:40 pm UTC

I think i would have gotten the joke faster if not for the RPS title. i was stuck on a Rock Paper Scissors joke before i read the subtext. very good joke after a quick google search. :D

User avatar
neoliminal
Posts: 626
Joined: Wed Feb 18, 2009 6:39 pm UTC

Re: "RPS" Discussion

Postby neoliminal » Mon Oct 05, 2009 3:41 pm UTC

RPN explaination for the start of WWII:

Germany Poland Invade
http://www.amazon.com/dp/B0073YYXRC
Read My Book. Cost less than coffee. Will probably keep you awake longer.
[hint, scary!]

User avatar
PhantomPhanatic
Posts: 84
Joined: Thu Nov 13, 2008 5:32 am UTC

Re: "RPS" Discussion

Postby PhantomPhanatic » Mon Oct 05, 2009 3:55 pm UTC

Not only do I use RPN consistently on my HP50g but I was planning a trip to a local hotdog stand today as well. Randall, get out of my head.

RPN is indeed fast. The only thing I don't like is that you lose the stack history when you do operations, but I think it's a fair price to pay.
We can lick gravity, but sometimes the paperwork is overwhelming.
-- Wernher Von Braun

Benson
Posts: 74
Joined: Wed Sep 10, 2008 4:15 am UTC

Re: "RPS" Discussion

Postby Benson » Mon Oct 05, 2009 4:09 pm UTC

Tofu-Sama wrote:
lulzfish wrote:To re-iterate some posts I've already made, graphing calculators are a colossal scam, and a monopoly.

Definitely a monopoly. The Faculty of Engineering at my university only certifies specific calculators (we have to get them stickered) for us to be able to use in tests, and they're all Texas Instruments. Then again, I've never used RPN, though it doesn't look like I'd particularly enjoy it.

If you're an engineer, I can assure you you'd enjoy it once you got the hang of it. Even constructing infix-notation equations (for symbolic differentiation, etc.) is faster and easier by pushing variable names on the stack and using the postfix operators to construct it. Every single person I know (without exception) who's used RPN for a month doesn't want to go back -- and I know a few, being a bit of an HP calculator evangelist.

But if your school has decided to be bastards about it, I guess you haven't much choice... :( The only opposition I hit was from the math department; the engineering departments were all pretty liberal about, with the overall practical notion that it's what problems you can solve, not which particular tools you use.

jc wrote:Infix calculators are sorta like the qwerty keyboard. They were both bumbling first tries to make something work with the hardware limitations of the time. Subsequent designs just blindly followed precedent, because "That's how it's done", with nobody but a few geeks wanting to think about whether there might be a better way. A lot of our UI design is like this. Once a precedent exists, it can take centuries for a different design to succeed. Manufacturers know that better designs usually fail because, no matter how bad the current design, most people prefer it to learning something new. Especially if it has anything to do with that horrible math stuff.


Not to revive the everlasting flamewar of keyboard layouts, but the difference is that RPN is objectively better by quite significant amounts (in terms of keystrokes saved, which is easily countable), while IMO dvorak is marginally better, but that practically _any_ layout, once learned, is nearly as good. (Of course, the keyboard research is a mess; there's issues of biased studies by Dvorak himself, and generally a wide scatter overall -- in no small part due to the difficulty of comparing speeds (due to the learning involved) and quantifying effort at all. The above is just my best impression of it...)

So it's arguable that the inertial course _might_ be best for keyboards, given the substantial cost of re-educating current typists, or dual-educating new typists with an eye to future change, and the limited gains. OTOH, a lot less people need to share a calculator than a keyboard, so it can be switched individually at minimal cost, and delivers rather more significant gains. The only reason I can see for the inertia in this case (given that HP actually has RPN calculators for all but the lowest market segments) is related to the educational system. :evil:

Technical Ben
Posts: 2986
Joined: Tue May 27, 2008 10:42 pm UTC

Re: "RPS" Discussion

Postby Technical Ben » Mon Oct 05, 2009 4:15 pm UTC

RogerMurdock wrote:Referring to postfix notation, also called Reverse Polish Notation.

http://en.wikipedia.org/wiki/Reverse_Polish_notation

In Reverse Polish notation the operators follow their operands; for instance, to add three and four, one would write "3 4 +" rather than "3 + 4". If there are multiple operations, the operator is given immediately after its second operand; so the expression written "3 − 4 + 5" in conventional infix notation would be written "3 4 − 5 +" in RPN: first subtract 4 from 3, then add 5 to that. An advantage of RPN is that it obviates the need for parentheses that are required by infix. While "3 − 4 * 5" can also be written "3 − (4 * 5)", that means something quite different from "(3 − 4) * 5". In postfix, the former would be written "3 4 5 * −", which unambiguously means "3 (4 5 *) −".


I once saw someone explain this to a room full of people. He got the same response as most of the posts here who "did not get it". Although both his explination and your post make perfect sense. It just takes a second to figure out what your talking about (if you not a mathy person) :P
It's all physics and stamp collecting.
It's not a particle or a wave. It's just an exchange.

Rplot
Posts: 13
Joined: Fri Feb 06, 2009 5:26 am UTC

Re: "RPS" Discussion

Postby Rplot » Mon Oct 05, 2009 4:34 pm UTC

One cute thing about the drawing is that the edges of the bun look like parentheses.

User avatar
Brooklynxman
Because I'm Awesome
Posts: 609
Joined: Tue Jan 20, 2009 4:27 pm UTC
Location: Here
Contact:

Re: "RPS" Discussion

Postby Brooklynxman » Mon Oct 05, 2009 4:36 pm UTC

I totally didnt get it last night, but knowing what RPN is now, it is hilarious
We figure out what all this means, then do something large and violent

The thing about changing the world...once you do it the world's all different.

I'm Angel. I beat the bad guys.

Spoiler:
Image

fatnickc
Posts: 7
Joined: Wed Aug 01, 2007 5:50 pm UTC
Location: London, UK

Re: "RPS" Discussion

Postby fatnickc » Mon Oct 05, 2009 4:48 pm UTC

Is this really Reverse Polish though? Personally I'd think of the bun as a function with the sausage as an operand, which would lead to it being just Polish notation.

User avatar
PM 2Ring
Posts: 3715
Joined: Mon Jan 26, 2009 3:19 pm UTC
Location: Sydney, Australia

Re: "RPS" Discussion

Postby PM 2Ring » Mon Oct 05, 2009 4:59 pm UTC

I smiled. I thought it could have been a little funnier though. And the mustard should perhaps be after the sausage.

I got it instantly, but I've been using RPN for over 35 years, and I'm currently involved in two threads on these fora discussing postfix notation: Scheme Makes Me Not Want to Code Ever Again and which asshat came up with infix?

I like comics like this one that merely require general mathematics / computer science knowledge. I often have to come to this subforum to fully appreciate the comics that have references to games or movies, since I haven't played many computer games, and I haven't watched many new movies in the last couple of decades.

godrik
Posts: 23
Joined: Wed Aug 06, 2008 10:37 am UTC

Re: "RPS" Discussion

Postby godrik » Mon Oct 05, 2009 5:16 pm UTC

The japanese are in advance: the reverse polish sushi would be a maki...

Pomegranete
Posts: 8
Joined: Tue Aug 18, 2009 12:29 am UTC

Re: "RPS" Discussion

Postby Pomegranete » Mon Oct 05, 2009 5:21 pm UTC

Wow, seriously.

I read this, and thought it was hilariously funny; I thought this was gonna go down great on the fora, but alas, it didn't; most people didn't understand this. Seriously?

Wow, I'm surprised.

Well, I for one heartily enjoyed this.

User avatar
You, sir, name?
Posts: 6983
Joined: Sun Apr 22, 2007 10:07 am UTC
Location: Chako Paul City
Contact:

Re: "RPS" Discussion

Postby You, sir, name? » Mon Oct 05, 2009 5:30 pm UTC

lol The goggles, they do nothing!
I edit my posts a lot and sometimes the words wrong order words appear in sentences get messed up.

User avatar
Earlz
Gets Obvious Implications
Posts: 785
Joined: Sat Jun 09, 2007 8:38 am UTC
Location: USA
Contact:

Re: "RPS" Discussion

Postby Earlz » Mon Oct 05, 2009 5:39 pm UTC

I know what RPN is.. but did not immediately connect the joke..

still not funny.. not even one of those after you go home and think about it and finally get it chuckles.. no.. I didn't laugh at all.. I've seen much better
My new blag(WIP, so yes it's still ugly..)
DEFIANCE!
Image
This is microtext. Zooming in digitally makes it worse. Get a magnifying glass.. works only on LCD

User avatar
sevatt
Posts: 1
Joined: Wed Jul 22, 2009 3:23 pm UTC
Location: Texas

Re: "RPS" Discussion

Postby sevatt » Mon Oct 05, 2009 5:47 pm UTC

The comic made me laugh, but I was thinking the mustard should have been drawn independent of the sausage. Then you can add everything off the stack.

Zylon
Posts: 142
Joined: Fri Jan 30, 2009 5:37 pm UTC

Re: "RPS" Discussion

Postby Zylon » Mon Oct 05, 2009 5:56 pm UTC

jc wrote:
Zylon wrote:Or, the far more likely explanation that almost all calculators use infix notation because almost all PEOPLE use infix notation, and that you're a loony.


Nah; you got the history wrong. People were doing arithmetic long before there were any calculating machines (mechanical or electronic), and they used postfix to do it.

Considering that postfix notation was only invented in 1954, this seems unlikely.

Meagen
Posts: 31
Joined: Wed Dec 27, 2006 2:26 pm UTC

Re: "RPS" Discussion

Postby Meagen » Mon Oct 05, 2009 6:07 pm UTC

I like getting a hotdog sausage with mustard (or even better, two) and eat it with a knife and fork, nibbling a bun on the side. Maybe I'll call that a Reverse Polish Hotdog from now on.

(Maybe it's just me, but when I get a hotdog most of my meal seems to consist of bun and mustard. In theory it's easier to eat on the go, but in practice I seem to always end up dribbling mustard over something. Much better to just sit down with a plate like a civilized person.)

User avatar
You, sir, name?
Posts: 6983
Joined: Sun Apr 22, 2007 10:07 am UTC
Location: Chako Paul City
Contact:

Re: "RPS" Discussion

Postby You, sir, name? » Mon Oct 05, 2009 6:15 pm UTC

sevatt wrote:The comic made me laugh, but I was thinking the mustard should have been drawn independent of the sausage. Then you can add everything off the stack.


That doesn't make sense. If you do that, you get mustard all over the bread, not just the sausage!

I think you need to see "mustard sausage" as a curried function. In LISP notation:

( Mustard Sausage Bread Bread ) <=> "Apply mustard to the sausage and the bread"
( ( Mustard Sausage) Bread Bread ) <=> " Apply mustard to the sausage, then apply the result to the bread"
I edit my posts a lot and sometimes the words wrong order words appear in sentences get messed up.

kafkadog
Posts: 9
Joined: Wed Aug 12, 2009 8:42 pm UTC

Re: "RPS" Discussion

Postby kafkadog » Mon Oct 05, 2009 6:20 pm UTC

I laughed out loud at this one. A good friend of mine just purchased an RPN calculator the other day. Get out of my friend's head, Randall!

gavinfoxx
Posts: 3
Joined: Mon Oct 05, 2009 6:15 pm UTC

Re: "RPS" Discussion

Postby gavinfoxx » Mon Oct 05, 2009 6:21 pm UTC

crzftx wrote:Ketchup doesn't belong anywhere near hotdog.


*checks where you are from*

Illinois. Of course! *checks some more* And within shouting distance of chicago!

I will say that ketchup is the only thing that makes *bad* hot dogs palatable! And in some parts of the world, you can't get good ones...

Zylon
Posts: 142
Joined: Fri Jan 30, 2009 5:37 pm UTC

Re: "RPS" Discussion

Postby Zylon » Mon Oct 05, 2009 6:23 pm UTC

You, sir, name? wrote:I think you need to see "mustard sausage" as a curried function.

A curry sausage? Disgusting!

marsman57
Posts: 67
Joined: Fri Jul 27, 2007 1:40 pm UTC

Re: "RPS" Discussion

Postby marsman57 » Mon Oct 05, 2009 6:29 pm UTC

Way way way too obscure Randall.

I went through a long phase of not getting it followed by a phase of thinking it was some sort of sex joke (the sausage is phallic and the bread...) followed by another phase of not getting it (the alt made no sense if it was a sex joke) followed by the forums.

Even understanding it now, I am not sure it would have been that funny as a comic alone. If anything, the alt would have been the only good part.

User avatar
ritvax
Posts: 104
Joined: Fri Jul 10, 2009 11:19 pm UTC
Location: New York

Re: "RPS" Discussion

Postby ritvax » Mon Oct 05, 2009 6:47 pm UTC

Zylon wrote:I must say, I'm honestly stunned how many people here didn't get such a simple reverse polish notation joke. It's not like RPN is particularly obscure. I'm terrible at math, have never used RPN, and haven't even thought about RPN in years, but I got the reference instantly.


Same here, I thought this forum was steeped in geekdom! I don't understand how you use RPN, but it is funny to use in a sentence because it sounds like a joke. "Then I used reverse polish notation, and BAM, it was obvious!"

Wait till I tell my engineer friends that I get jokes!
I wish I was running VMS v.6.5

User avatar
SpikedMath
Posts: 10
Joined: Sat Oct 03, 2009 10:47 pm UTC
Contact:

Re: "RPS" Discussion

Postby SpikedMath » Mon Oct 05, 2009 7:26 pm UTC

This comic was good, better than last Friday's in my opinion ^_^
Math - It's in you to give.

User avatar
phillipsjk
Posts: 1213
Joined: Wed Nov 05, 2008 4:09 pm UTC
Location: Edmonton AB Canada
Contact:

Re: "RPS" Discussion

Postby phillipsjk » Mon Oct 05, 2009 7:57 pm UTC

ritvax wrote:Same here, I thought this forum was steeped in geekdom! I don't understand how you use RPN, but it is funny to use in a sentence because it sounds like a joke. "Then I used reverse polish notation, and BAM, it was obvious!"


Maybe the sexually explicit comics of late have drawn a new audience that is mildly offended by math/CS jokes.

I was one of the people who go it right away, but did not find it too funny (I smiled).

To the people complaining about the mustard on the sausage: the Caption text reads: "It looks good, but needs more postfixins." I think that implies that Randal though about it, and decided against drawing the condiments separately. You can call it "artistic license" if it makes you feel better.

Edit: On the comic page:
XKCD wrote:
Comic today's you confuses here click if.

Did you get the number on that truck?

User avatar
SpikedMath
Posts: 10
Joined: Sat Oct 03, 2009 10:47 pm UTC
Contact:

Re: "RPS" Discussion

Postby SpikedMath » Mon Oct 05, 2009 8:18 pm UTC

Randall also posted a link just below the xkcd header image. It reads:

"COMIC TODAY'S YOU CONFUSES HERE CLICK IF."
Math - It's in you to give.

User avatar
Lothar
Posts: 63
Joined: Sat Dec 23, 2006 11:37 am UTC
Location: Berlin, Germany
Contact:

Re: "RPS" Discussion

Postby Lothar » Mon Oct 05, 2009 8:50 pm UTC

I found it absolutely hilarious. Haven't laughed this much at a comic in a while. Simply brilliant.
Always program as if the person who will be maintaining your program is a violent psychopath that knows where you live.

If you're not part of the solution, you're part of the precipitate.

1+1=3 for large values of 1.

User avatar
PhoenixEnigma
Posts: 2303
Joined: Fri Sep 18, 2009 3:11 am UTC
Location: Sasquatchawan, Canada
Contact:

Re: "RPS" Discussion

Postby PhoenixEnigma » Mon Oct 05, 2009 8:55 pm UTC

SpikedMath wrote:Randall also posted a link just below the xkcd header image. It reads:

"COMIC TODAY'S YOU CONFUSES HERE CLICK IF."


I just saw that had been added, and I find it multiplies the funny-factor of the comic by a fairly large number. Bravo!
"Optimism, pessimism, fuck that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work." -Elon Musk
Shivahn wrote:I am a motherfucking sorceror.

qbg
Posts: 586
Joined: Tue Dec 18, 2007 3:37 pm UTC

Re: "RPS" Discussion

Postby qbg » Mon Oct 05, 2009 9:12 pm UTC

Somebody needs to integrate this joke into Factor.

Burn0ut07
Posts: 8
Joined: Sun Feb 17, 2008 11:52 am UTC

Re: "RPS" Discussion

Postby Burn0ut07 » Mon Oct 05, 2009 9:22 pm UTC

Cynical Idealist wrote:
jc wrote:
bridgeyman wrote:I was calculator shopping yesterday, and just barely explained Reverse Polish Notation to one of my friends! I guess this is my "get out of my head, Randall" moments.


One of the fun way to debunk claims about rationality in The Market is that a number of usability studies have shown that nearly everybody (except the occasional math wiz) can use RPN calculators more easily than the infix kind. But almost all commercially available calculators use infix notation. This is just one of many examples showing that the commercial world isn't concerned with usability.

This has led to at least one loss of mathematical understanding. Try asking people what the value of 2+2*2 is, and you'll see it. At least here in the US, nearly everyone now answers 8, and you can find it difficult to explain why the correct answer is 6. Very often, people will "prove" that you're wrong by picking up a calculator, typing "2+2*2=", and showing that the answer is 8. The calculator can't be wrong; it must be mathematics that's wrong.

One thing I like about that "proof by calculator" is that you type the '=' at the end, which looks very much like an RPN operator. If it were infix, you'd expect the calculator to wait until you type the result, and then it would show a T or F, depending on whether you typed the correct result. So "infix" calculators not only fail to calculate correctly by ignoring operator precedence; they actually implement a mixture of infix and RPN notation.


I remember reading a story about that. The frustrated person who knew about order of operations looked for some way to prove it, but didn't have a graphing calculator (which generally follow the rules), so he started up Excel. The consensus was that Excel is broken.


Not sure what idiots you talk to but everyone I talk to knows order of operations. Also as already mentioned all scientific calculators use correct order of operations not to mention just using a computer's calculator since they also have a scientific mode.

User avatar
Nath
Posts: 3148
Joined: Sat Sep 08, 2007 8:14 pm UTC

Re: "RPS" Discussion

Postby Nath » Mon Oct 05, 2009 11:23 pm UTC

crzftx wrote:
odie wrote:i have to agree, more postfixins are needed, personally i like tomato sauce mustard, sweet pickle relish, a dill pickle spear, tomato slices or wedges, pickled sport peppers, a dash of celery salt, and onion on my hotdogs (for those Americans out there tomato sauce = ketchup)

Edit: i forgot to say what an awesome comic this is, it's the first one in a long time that's required me to think. its not the funniest but its going down as a 'great' in my book


Ketchup doesn't belong anywhere near hotdog.

Or a Polish sausage, for that matter. But then, relish, dill and tomato have no place on a Polish, either. Mustard, grilled onions, and optionally peppers; that's all you need. Polish != Chicago style. I assume the onions were the mixing postfixins referred to by the alt text.

On topic, this was a good comic. There was a place right next to my undergrad CS building (where I learned about RPN) that had good Maxwell Street Polish sausages, as described above.

sluissa
Posts: 1
Joined: Mon Oct 05, 2009 11:33 pm UTC

Re: "RPS" Discussion

Postby sluissa » Mon Oct 05, 2009 11:38 pm UTC

Thanks, Randall, for deciding what I was going to have for dinner.

Spoiler:
Image


btw, yes, registered, just to post this.

User avatar
Cynical Idealist
Posts: 1124
Joined: Mon Sep 15, 2008 10:48 pm UTC

Re: "RPS" Discussion

Postby Cynical Idealist » Tue Oct 06, 2009 12:04 am UTC

Burn0ut07 wrote:
Cynical Idealist wrote:<snip>

Not sure what idiots you talk to but everyone I talk to knows order of operations. Also as already mentioned all scientific calculators use correct order of operations not to mention just using a computer's calculator since they also have a scientific mode.

Please reread my post. I *read* something about it, it didn't happen to me.
The internet removes the two biggest aids in detecting sarcasm:
1)The tone of voice
2)the assumption that the other person is sane
Elvish Pillager wrote:See? All the problems in our society are caused by violent video games, like FarmVille.

User avatar
sableye22
Posts: 38
Joined: Sun Dec 21, 2008 10:37 pm UTC
Location: YOUR MO-- forget it.

Re: "RPS" Discussion

Postby sableye22 » Tue Oct 06, 2009 1:04 am UTC

jc wrote:This has led to at least one loss of mathematical understanding. Try asking people what the value of 2+2*2 is, and you'll see it. At least here in the US, nearly everyone now answers 8, and you can find it difficult to explain why the correct answer is 6. Very often, people will "prove" that you're wrong by picking up a calculator, typing "2+2*2=", and showing that the answer is 8. The calculator can't be wrong; it must be mathematics that's wrong.


That made me sad. But at least I learned a new random fact today. Knowledge is power! :mrgreen:
You don't have to spend, you just have to pretend.

User avatar
Sarda
Posts: 42
Joined: Wed Apr 29, 2009 8:23 pm UTC

Re: "RPS" Discussion

Postby Sarda » Tue Oct 06, 2009 1:10 am UTC

I really don't understand how postfix is any better than infix. Here's my view:
Infix

Code: Select all

Okay, where do we start?
6
All right, now what?
*
Okay, we're multiplying something.  What are we multiplying by 6?
9
9.  6 * 9 = 42.  Got it!

Postfix

Code: Select all

Okay, where do we start?
6
Next number?
9
Anything else?
*
6 * 9 = 42.  Got it!


And about order of operations, anyone who doesn't know it needs to go back to elementary school. It's just as easy to learn that as it is to get the hang of knowing that 6 4 2 7 3 + * + - is 18. Yeah, it took me a while to get that one, but less time than it would have to learn 2 * (7 + 3) + 4 - 6. Parentheses are there to make things look nice, unlike a long string of operands.

And, if you're wondering about my math in the earlier examples, you're not a true xkcdian.
If P AND NOT P then the lotto numbers will be 4, 19, 23, 194, the fine structure constant, and Birmingham.


Return to “Individual XKCD Comic Threads”

Who is online

Users browsing this forum: No registered users and 93 guests