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Author Topic: Not TRYING to start a flame war honest.  (Read 4888 times)
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We don't teach kids to do math in RPN
Maybe we should.   have you seen those math "puzzles" that pop on facebook now and then" "Evaluate: 6-1*0+2/2", and how many people get them wrong ("hey, I typed it just likes it's shown into my calculator and that's what I got...")

While that might help with basics... it would cause problems for those who get around to higher math.  Which would also require restructuring how math is done.  The algebraic method is inherrent in the approach/philosophy of all western mathematics.
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Give a third grader an algebraic calculator and they have no difficulty using it even if they have never seen one before.
Until they try to do something more complex than "a + b" or "c * d" and discover the Joys of Operator PrecedenceTMsmiley-evil

I think it's possible that RPN is not so much inherently "counter-intuitive" as "counter-experience", because we're English speakers who have already had a lot of exposure to algebraic notation by third grade.  It would be interesting to see some actual study of whether readers of right-to-left written languages have the same initial difficulty.

I liked the relative consistency and simplicity of APL, which uses infix notation, but is strictly right-to-left evaluation without precedence (except that you can still use parens to explicitly force priority of subexpressions).
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I think it's possible that RPN is not so much inherently "counter-intuitive" as "counter-experience", because we're English speakers who have already had a lot of exposure to algebraic notation by third grade.

There's the nub. This is not quite similar, but sorta, to learning to read left-right / top-down. We train our brains to do things in a particular way, and then there's tons of positive reinforcement of that way, because of network effects.

To a man, everyone I know who has taken the time to learn RPN has ended up preferring it. In fact, I have read explanations of RPN which make a good case that it's actually more intuitive to the way people think about problem solving. I should try to find that, but I'm in the middle of a Charles Stross book. (Not a particularly good one, BTW. He's no Scalzi or Stephenson, but some people really like him. Well, perhaps his other works are better.)
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Give a third grader an algebraic calculator and they have no difficulty using it even if they have never seen one before.
Until they try to do something more complex than "a + b" or "c * d" and discover the Joys of Operator PrecedenceTM.  smiley-evil

I think it's possible that RPN is not so much inherently "counter-intuitive" as "counter-experience", because we're English speakers who have already had a lot of exposure to algebraic notation by third grade.  It would be interesting to see some actual study of whether readers of right-to-left written languages have the same initial difficulty.

I liked the relative consistency and simplicity of APL, which uses infix notation, but is strictly right-to-left evaluation without precedence (except that you can still use parens to explicitly force priority of subexpressions).


Algebraic notation is inherrent to western mathematics.  Changing to RPN would involve a lot more than simply changing how to do basic calculations.

BTW significant portions of Algebraic notation was invented by Arabs whom I believe write right to left.
« Last Edit: August 21, 2012, 09:39:07 pm by wanderson » Logged

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RPN is only counter-intuitive in the sense that any other new concept is. Have used HP RPN calculators for decades. Can run circles around anyone with an algebraic calculator, and with better accuracy to boot. This wouldn't be the case if it hadn't become pretty darned intuitive.

There is a bit of a learning curve, but the upside is that no one borrows your calculator (at least not for long) smiley-lol  The look of consternation on peoples' faces as they search for the "=" button is worth orders of magnitude more than the modest learning curve.
« Last Edit: August 21, 2012, 10:03:27 pm by Jack Christensen » Logged

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Algebraic notation
...has little to do with infix vs postfix operator precedence.  Most actual math gets done with two-dimensional notation that isn't in any sense "pure" (consider Integrals, with the operands in between pieces of the operators, or "2x" where operators are simply omitted.)

(Hmm.  Laws of math:  a b + c * = a c * b c * +  ?)
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Algebraic notation
...has little to do with infix vs postfix operator precedence.  Most actual math gets done with two-dimensional notation that isn't in any sense "pure" (consider Integrals, with the operands in between pieces of the operators, or "2x" where operators are simply omitted.)

(Hmm.  Laws of math:  a b + c * = a c * b c * +  ?)


infix makes use of the original algebraic notation--hence why it is intuitive.  I mean by that, if you understand the basic notation, then the use of infix (including operator precedence) would come naturally.  RPN (of which I am a fan for calculator use) requires first mentally shuffling the operations to meet the need of the calculator which is opposed to the needs of the standard notation.

After working a lifetime with Engineers (most of whom prefer RPN calculators--at least the older ones, since that seems to be changing), I have never encountered anyone who used RPN to perform symbolic algebra or calculus calculations. 
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Forth is OOP through builds-does regardless of how it's done. I feel very sorry for those who have tried and can't see it. Forth, like C++, can self-extend as part of the language.

Same thing goes with stack operating. You can embrace the stack or you can hissy-fit over RPN. Again, I feel sorry for those that miss the boat.

Maybe it's just too simple for those who need lines to color inside. I've seen that with math and science too, otherwise smart people who missed lessons because they were looking for the more complex 'more' they live convinced there must be.

Dropouts and their attitudes towards science is an apt analogy to anyone who refuses to learn something (as opposed to see it in the light of something else) but is ego-bound to find any way the can to put it down. We can all find faults with the Arduino IDE but how often does someone go ape$#!+ over it and C++ without having learned most of the language and showing it? Show them something with with pointers and they haven't a clue, but this IDE and C++ sucks!

I'm not going to bother with more words. It's not something that's about words anyway. You either understand or you don't. You either like it or you don't. If you don't understand it as opposed to your ideas of it (and all the crap you can dig up to fling ignoring everything but the crap because ego won't let the ideas be changed, no way, ego can't be wrong) then making absolute statements about what it is is just opinion disguised as wisdom, aka BS.
 
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I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

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I don't think you connected the grounds, Dave.
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I think this has now gone way beyond "bitand, bitor" etc.

Can we close the thread now, please?
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