I love shooting myself in the foot
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@HardwareGeek said:
I suspect it takes very little education/experience to overcome a bias toward infix or postfix preference
RPN exists solely for computers (well, calculators) because of ease of implementation. No human does math in real life in that way, so I'd be surprised if anyone has or would ever develop a preference for it.
On a broader topic, there has been some research on how language shapes the thought process but like most other things in psychology it's plagued by badly conducted trials, lack of reproducibility, and general lack of interest. See http://en.wikipedia.org/wiki/Language_and_thought and note how it starts off warning you about the lack of sources.
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@Arnavion said:
The input is 1 2 3 4 5 + * / - What is the operation performed when the + is encountered? The addition of 4 and 5.
Now, see, you are being deliberately imprecise. If the arguments are popped off the stack, then the operation is the addition of 5 and 4. The addition of 4 and 5 is NOT the same as the addition of 5 and 4, in any way except the result. By a happy accident, if you screw up the order of the operands, you'll still get the correct result IF the operator is commutative, but this philosophy will get you into trouble when you start dealing with operators that are NOT commutative. The order of operands in the RPN directly associates with the order of operands in infix notation; to argue otherwise is madness.
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@anotherusername said:
If the arguments are popped off the stack, then the operation is the addition of 5 and 4.
It doesn't have to be. In my pseudocode, replace var1 + var2 with var2 + var1. Are you saying that every single RPN calculator ever programmed in the world must necessarily do var1 + var2 ? What's your source?
@anotherusername said:
The addition of 4 and 5 is NOT the same as the addition of 5 and 4, in any way except the result.
And, pray tell, in what ways they are different? And don't remind me that they're different for non-commutative operators (which you seem keen on repeating over and over again even though I was the one who brought them up first so I obviously know what they are). I'm talking about only this one sentence you said here, that is about addition.
@anotherusername said:
to argue otherwise is madness.
The one who says that 4 + 5 is not the same as 5 + 4 "except for the result" should not be talking to others about madness.
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@Arnavion said:
And, pray tell, in what ways they are different?
In the sense that a calculator or computer isn't aware that addition is commutative, and it just does exactly what you tell it to do. If you write a function that takes two arguments and adds them, it's not going to randomly decide to swap the arguments now and then just because it can do so without changing the result.@Arnavion said:The one who says that 4 + 5 is not the same as 5 + 4 "except for the result" should not be talking to others about madness.
This:
MOV DX, 4
ADD DX, 5is not the same as this...
MOV DX, 5
ADD DX, 4The result may be the same, but they are not the same.
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@Arnavion said:
@HardwareGeek said:
They don't usually write it using postfix notation, and they may not use a stack, but anyone doing math must have both operands available before performing an operation on them, so I'd they do, in some sense, do math that way. @Arnavion said:I suspect it takes very little education/experience to overcome a bias toward infix or postfix preference
RPN exists solely for computers (well, calculators) because of ease of implementation. No human does math in real life in that way,
so I'd be surprised if anyone has or would ever develop a preference for it.
"Preference" is not quite the right word for the concept I had in mind, but I couldn't think of a better way of expressing "relative ease of understanding and using one notation vs. the other" concisely. As to developing a preference, HP has sold a lot of calculators over the years, and computer programs that emulate HP calculators exist. Either some people prefer RPN, or they want unique features of those calculators enough to put up with a non-preferred notation.@Arnavion said:
On a broader topic, there has been some research on how language shapes the thought process but like most other things in psychology it's plagued by badly conducted trials, lack of reproducibility, and general lack of interest.
Well, yeah; it's "soft" science. But that is the idea I had in mind, does human language influence thought process related to this specific topic? @Arnavion said:See http://en.wikipedia.org/wiki/Language_and_thought and note how it starts off warning you about the lack of sources.
While that is not a good thing, it doesn't necessarily mean the article is inaccurate; it just makes it much harder to verify its accuaracy. Many factually accurate articles lack citations to identify the source of those facts, and lots of lunatic-fringe pseudoscience has abundant citations to identify the sources of its "facts." It all depends on whether an editor has taken the time to find such sources and paste references to them into the article.
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@anotherusername said:
Guess who gets the pedantic dickweed award for October?This:
MOV DX, 4
ADD DX, 5is not the same as this...
MOV DX, 5
ADD DX, 4The result may be the same, but they are not the same.
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@dkf said:
@anotherusername said:
Guess who gets the pedantic dickweed award for October?This:
MOV DX, 4
ADD DX, 5is not the same as this...
MOV DX, 5
ADD DX, 4The result may be the same, but they are not the same.
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@mott555 said:
In past times, this entire thread would have been a great blakeyrant honeypot.
Goddammit people! Who gives a fuck about some obscure bullshit calculator notation?! You should be out writing good software, trolling Lotus Notes aficionados on twitter and fapping to ponies! I have a fucking framework to do calculations for me so I don't have to think about this sort of thing!
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@dkf said:
@anotherusername said:
Finally! Now I can rest easy and wait for November.
Guess who gets the pedantic dickweed award for October?This:
MOV DX, 4
ADD DX, 5is not the same as this...
MOV DX, 5
ADD DX, 4The result may be the same, but they are not the same.
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@Arnavion said:
I copied this into my Factor REPL and got 25/27. You have the order wrong on your commutative operators.The input is 1 2 3 4 5 + * / - .
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@Arnavion said:
The input is 1 2 3 4 5 + * / - What is the operation performed when the + is encountered? The addition of 4 and 5. What is the operation performed when the * is encountered? The multiplication of 3 and 9. What is the operation performed when the / is encountered? The division of 27 by 2. What is the operation performed when the - is encountered? The subtraction of 1 from 13.5. The result is 12.5. The final computation is equivalent to the infix "(((4 + 5) * 3) / 2) - 1" which performs the same steps in the same order as the RPN.
Except it isn’t. My HP 50g comes up with the .926 number (or 25/27 in exact mode), RealCalc on my phone comes up with the .926 number, [url=http://icrank.com/data/calculator/calc_app.htm]this online calculater[/url] comes up with the .926 number. No calculator operates in the manner you describe. They all do your “var2 op var1”. “2 ENTER 3 /” results in .6666667, not 1.5.
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@Sir Twist said:
Yeah, all the RPN calculators I've ever fiddled with (and the one I wrote, too, but that's somewhat beside the point) used the operands in that order too. But if someone's going to argue that their calculator does it backward, then at least it should do them consistently backward. (((4 + 5) * 3) / 2) - 1 is not the same expression as (((5 + 4) * 3) / 2) - 1, despite the fact that they are algebraically equivalent and you can transform one into the other simply by applying the commutative property.@Arnavion said:
The input is 1 2 3 4 5 + * / - What is the operation performed when the + is encountered? The addition of 4 and 5. What is the operation performed when the * is encountered? The multiplication of 3 and 9. What is the operation performed when the / is encountered? The division of 27 by 2. What is the operation performed when the - is encountered? The subtraction of 1 from 13.5. The result is 12.5. The final computation is equivalent to the infix "(((4 + 5) * 3) / 2) - 1" which performs the same steps in the same order as the RPN.
Except it isn’t. My HP 50g comes up with the .926 number (or 25/27 in exact mode), RealCalc on my phone comes up with the .926 number, this online calculater comes up with the .926 number. No calculator operates in the manner you describe. They all do your “var2 op var1”. “2 ENTER 3 /” results in .6666667, not 1.5.
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@anotherusername said:
But if someone's going to argue that their calculator does it backward, then at least it should do them consistently backward.
OK, I see what you’re saying. “1 2 3 4 5 + * / -” actually evaluates to “1 - (2 / (3 * (4 + 5)))”. Everybody has been wrong.
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@Sir Twist said:
No calculator operates in the manner you describe. They all do your “var2 op var1”.
Bah, my foot is in mouth here. I was taught otherwise in school but I can't find any sources to corroborate it. The wiki article on RPN even requires that the order of non-commutative operations is always var2 op var1
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@Sir Twist said:
@anotherusername said:
But if someone's going to argue that their calculator does it backward, then at least it should do them consistently backward.
OK, I see what you’re saying. “1 2 3 4 5 + * / -” actually evaluates to “1 - (2 / (3 * (4 + 5)))”. Everybody has been wrong.
It's like I've been posting to a different thread or something:
@PedanticCurmudgeon said:@Arnavion said:
You guys are the worst, and Sir Twist, you are the worst of the worst!
I copied this into my Factor REPL and got 25/27. You have the order wrong on your commutative operators.The input is 1 2 3 4 5 + * / - .
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@PedanticCurmudgeon said:
@Sir Twist said:
@anotherusername said:
But if someone's going to argue that their calculator does it backward, then at least it should do them consistently backward.
OK, I see what you’re saying. “1 2 3 4 5 + * / -” actually evaluates to “1 - (2 / (3 * (4 + 5)))”. Everybody has been wrong.
It's like I've been posting to a different thread or something:
@PedanticCurmudgeon said:@Arnavion said:
You guys are the worst, and Sir Twist, you are the worst of the worst!
I copied this into my Factor REPL and got 25/27. You have the order wrong on your commutative operators.The input is 1 2 3 4 5 + * / - .
Well, there's also Ronald's post, where he (she?) correctly pointed out that the expression (((4 + 5) * 3) / 2) - 1 would actually be 4 5 + 3 * 2 / 1 - in RPN.
Oh, and getting the wrong result would indicate that the order was wrong on the non-commutative operators. Getting the order wrong on the commutative operators wouldn't change the result.
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@anotherusername said:
Well, there's also Ronald's post, where he (she?) correctly pointed out that the expression (((4 + 5) * 3) / 2) - 1 would actually be 4 5 + 3 * 2 / 1 - in RPN.
I'm now a gender-neutral reference about RPN.
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@
said:
@anotherusername said:
Well, I tend to think of people as their avatar. I realise it's probably wildly inaccurate in most cases.Well, there's also Ronald's post, where he (she?) correctly pointed out that the expression (((4 + 5) * 3) / 2) - 1 would actually be 4 5 + 3 * 2 / 1 - in RPN.
I'm now a gender-neutral reference about RPN.
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@anotherusername said:
[quote user="
Well, I tend to think of people as their avatar. I realise it's probably wildly inaccurate in most cases.[/quote]Well, there's also Ronald's post, where he (she?) correctly pointed out that the expression (((4 + 5) * 3) / 2) - 1 would actually be 4 5 + 3 * 2 / 1 - in RPN.
I'm now a gender-neutral reference about RPN.
I am running a scientific experiment to confirm an hypothesis which explains why Ben L was always brown-nosing Morbius even if Morbius was not reciprocating.
If you want to do an experiment yourself try switching to a cute, vulnerable cat avatar... but lock your doors at night especially if you live in Wisconsin.
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@Ronald said:
@anotherusername said:
[quote user="
Well, I tend to think of people as their avatar. I realise it's probably wildly inaccurate in most cases.Well, there's also Ronald's post, where he (she?) correctly pointed out that the expression (((4 + 5) * 3) / 2) - 1 would actually be 4 5 + 3 * 2 / 1 - in RPN.
I'm now a gender-neutral reference about RPN.
I am running a scientific experiment to confirm an hypothesis which explains why Ben L was always brown-nosing Morbius even if Morbius was not reciprocating.
If you want to do an experiment yourself try switching to a cute, vulnerable cat avatar... but lock your doors at night especially if you live in Wisconsin.
[/quote]I'd be tempted, but that describes the girl I've been chasing. Too weird.
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@PedanticCurmudgeon said:
You guys are the worst, and Sir Twist, you are the worst of the worst!
I'm not sure you’re allowed to reassign an award someone else created without permission.
Actually, I failed to notice the second page before replying.
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@Sir Twist said:
There isn't an Internet Police, and I'm not the Internet dictactor, but if I were, I would make not reading the thread before replying a much more serious offense than jokingly stealing someone else's award who isn't posting any more.@PedanticCurmudgeon said:
You guys are the worst, and Sir Twist, you are the worst of the worst!
I'm not sure you’re allowed to reassign an award someone else created without permission.
Actually, I failed to notice the second page before replying.
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@PedanticCurmudgeon said:
There isn't an Internet Police, and I'm not the Internet dictactor, but if I were, I would make not reading the thread before replying a much more serious offense than jokingly stealing someone else's award who isn't posting any more.
I usually don't even read an entire post before replying. You expect people to read a whole thread?
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This is the internet, so realistically I expect them to make unwarranted assumptions, jump to conclusions, miss the point, and in general respond to what their shoulder aliens tell them they just read, but I'd really like it if they read the whole thread first.
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@Ronald said:
I usually don't even …
Blah blah blah. Whatever.
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@anotherusername said:
I tend to think of people as their avatar. I realise it's probably wildly inaccurate in most cases.
In real life, I've got a mustache that will celebrate its 29th birthday next week. That's for your files. The avatar was selected years ago to illustrate a literal meaning of the expression "out of the mouths of babes", and I just stuck with it.
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@HuskerFan90 said:
@Arnavion said:
@Ronald said:
You simply point your mobile at the QR code on the tv screen, you choose one of the 3 categories (OMG, WTF, LOL) and instantly a 140 character summary of the story would be posted under your twitter account, adding the category hashtag.
Pssh. If you knew anything about college students, you'd know to let them choose all three categories. All the time. By default, even.
You guys forgot about YOLO.
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@Ronald said:
I am running a scientific experiment to confirm an hypothesis which explains why Ben L was always brown-nosing Morbius even if Morbius was not reciprocating.
See, the problem with the "scientific" experiment is that the experimenter is an active participant and there is no control group.
Besides, you'll always be Ronald.
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@Ben L. said:
@Ronald said:
I am running a scientific experiment to confirm an hypothesis which explains why Ben L was always brown-nosing Morbius even if Morbius was not reciprocating.
See, the problem with the "scientific" experiment is that the experimenter is an active participant and there is no control group.
I don't think you understand what a scientific experiment is. I'll have to put that in my notes.
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@da Doctah said:
I've got a mustache that will celebrate its 29th birthday next week.
I'm participating in movember this year. This will be the first time in my 32 years that I will be purposefully growing facial hair...
