### Email Archive: gdalgorithms-list (read-only)

 Re: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Peter Dimov - 2001-10-06 12:56 ```From: "Brian Hook" > I think most papers would be a lot more readable for non-math-stud > programmers if they just showed pseudocode instead of the math notation, > but that's selfish desire more than anything else. It's also a cheap > rationalization for my sucky math kung fu =) Most algorithms would probably be much more readable for non-programmer mathematicians if they just used the familiar sigma instead of strange for loop constructs. :-) -- Peter Dimov Multi Media Ltd. ```

RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) Jason Dorie <jason.dorie@bl...>
 RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Brian Hook - 2001-10-05 22:33 ```> Behalf Of Jason Dorie > > I've found mathematicians in general love this. Having > very little formal math background, I have difficulty with > mathematical notation and language, but grasp complex > concepts easily when they're put into english or code. This is common, especially with self-taught computer programmers. My math is complete and utter crap, and for the longest time I just felt it was because I was fundamentally stupid. But once I started "decoding" the papers, I would sit back and think "Jeez, if they'd just SAID that, I would have understood it an hour ago!" The dilemma is that most math notation is both precise and compact, which is why it's popular. The first time some people see sigma or double sigma they panic -- it looks like scary math stuff. Then you say "Oh, yeah, that's a for loop" then it's not so frightening. Other classic cases include the use of set notation (for "I" in R3) and the constant use of greek symbols instead of variable names. For me, I don't think in terms of "lambda" or "mu", I think "that squiggly thing" and "that other squiggly thing". It's all Greek to me (*ducks*). In the end though I think much of this obfuscation happens because people want to be precise and they want to use the vernacular of their peers (often other people that know all the lingo). Hell, vector notation frightened the hell out of me 10 years ago, and then someone explained what vectors and things like the dot and cross product were, and I was like "Oh, well crap, why didn't someone SAY so?!" I think most papers would be a lot more readable for non-math-stud programmers if they just showed pseudocode instead of the math notation, but that's selfish desire more than anything else. It's also a cheap rationalization for my sucky math kung fu =) Brian ```

 RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Michael Pohoreski - 2001-10-05 22:42 ```Yeah, I don't get why people tend to overly complicate things either. *cough due-to-false-sense-of-job-security? cough* I agree, the notation can get in the way at times. There is something to be said for conciseness and compactness, but not at the cost of obfuscation !! Notice the parallel to programming. ;-) At least I'm not put off by the notation as I used to be. Sometimes I wonder if mathematicians use so many foreign glyphs because they can. ;-) I'm finding that if one can understand the terminology, the notation isn't as bad. i.e. orthogonal-orthonormal basis what? ;-) I'm just glad we don't have to deal with super & sub scripts in code :) "But teacher, it's all Greek!" "Well, you'd better learn to read Greek then!" ```

 RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Rachid El Guerrab - 2001-10-05 22:59 ```a word for tha mathematiciens here.. those notations help a lot in reasoning. not just for artistic issues ;) they put an equation or a function in the math format, so they can quickly figure out some properties for it.. not an easy thing to do if u read the code (or even in english). it was invetend as a tool.. just like when u visualize a piece of geometry instead of talking about it. just my 2 cents.. ~Rachid Midway -----Original Message----- From: Michael Pohoreski [mailto:MPohoreski@...] Sent: Friday, October 05, 2001 3:43 PM To: GDAlgorithms-list@... Subject: RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) Yeah, I don't get why people tend to overly complicate things either. *cough due-to-false-sense-of-job-security? cough* I agree, the notation can get in the way at times. There is something to be said for conciseness and compactness, but not at the cost of obfuscation !! Notice the parallel to programming. ;-) At least I'm not put off by the notation as I used to be. Sometimes I wonder if mathematicians use so many foreign glyphs because they can. ;-) I'm finding that if one can understand the terminology, the notation isn't as bad. i.e. orthogonal-orthonormal basis what? ;-) I'm just glad we don't have to deal with super & sub scripts in code :) "But teacher, it's all Greek!" "Well, you'd better learn to read Greek then!" _______________________________________________ GDAlgorithms-list mailing list GDAlgorithms-list@... https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list ```

 Re: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Ron Levine - 2001-10-05 23:56 ```"Michael Pohoreski" wrote: >At least I'm not put off by the notation as I used to be. Sometimes I >wonder if mathematicians use so many foreign glyphs because they can. No, it's because you soon run out of roman letters with mnemonic value. The point is that different things need different names, a principle all too often ignored among non-mathematicians.. At the same time, names or symbols ought to have mnemonic value, something that suggests the thing named. And the Greek alphabet is handy because it maps pretty well to the Roman alphabet, and gives distinct but analogous symbols. For example, all too often in forums such as this, you see people struggling with transformations among several different coordinate systems, while trying to use the same triplet of symbols (x, y, z) to name the coordinates with respect to all of them. There is no way to make sense out of such discourse. If you have three different coordinate systems (say, modeling, world, view, etc), in a single discussion then you MUST use different symbols for the coordinates with respect to each. A mathematician might use (x, y, z), (X, Y, Z) (paying attention to case) and (xi, eta, zeta) (or rather the squiggly lower case greek letters whose English names are "xi", "eta", "zeta", and are the greek equivalents of x, y, z), then perhaps (XI, ETA, ZETA ) (capital greek x, y,z) if there is a fourth coordinate system in the picture. Or, you could use (x, y, z) with various kinds of subscripts, primes, superscripts, whatever, just to be sure that (1) different things have different names and (2) names have some mnemonic value. If you rule out the use of greek alphabet and other special character sets, then you are going to be symbol-poor and will have a harder time expressing yourself precisely and concisely. Ron ```

 Re: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Ron Levine - 2001-10-05 23:59 ```Brian Hook wrote: >..... Hell, vector >notation frightened the hell out of me 10 years ago, and then someone >explained what vectors and things like the dot and cross product were, >and I was like "Oh, well crap, why didn't someone SAY so?!" > They probably DID say so. At least _I_ said so when I was teaching calculus. Maybe you were asleep in the back row. Or perhaps in the student union playing video games? Ron ```

 RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Jason Dorie - 2001-10-06 00:13 ```I'm fully aware that mathematical notation is useful, and I understand why. I'm a lot more likely to say "virtual destructor" than "automatically overridable cleanup mechanism" - To a C++ programmer, the first phrase is more concise and implies the exact implementation. In math, you can write a1 + a2 + a3 + a4 ..., or use the sigma notation. My problem isn't as much in the notation as it is in the presentation. Most docs by mathmaticians has a nice, digestable english-like introduction, followed by intense math. I'd simply like the opening paragraph to include a little more algorithmic description in laymans terms, if possible, since what follows it is often useless to me. As for Ron's coordinate space example, I have an easier time digesting ScreenPos, WorldPos, and ClipPos than (x,y,z), (x',y',z') and (x^,y^,z^) or the like. To me, when reading -1 T (x',y',z') = (x,y,z) * V[T] * T [C] * (x^,y^,z^) the purpose would be clearer if written ScreenPos = WorldPos * View * CamTranspose * ClipTranspose The example is nonsense, but it's akin to choosing meaningful variable names. Many are guilty of obfuscating rather than clarifying, both mathematicians and programmers alike. Use the math notation when presenting proofs or properties, but for a discussion, english can often (not always) do as good a job. Jason Dorie BBG -----Original Message----- From: gdalgorithms-list-admin@... [mailto:gdalgorithms-list-admin@... Behalf Of Rachid El Guerrab Sent: Friday, October 05, 2001 4:02 PM To: GDAlgorithms-list@... Subject: RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) a word for tha mathematiciens here.. those notations help a lot in reasoning. not just for artistic issues ;) they put an equation or a function in the math format, so they can quickly figure out some properties for it.. not an easy thing to do if u read the code (or even in english). it was invetend as a tool.. just like when u visualize a piece of geometry instead of talking about it. just my 2 cents.. ~Rachid Midway -----Original Message----- From: Michael Pohoreski [mailto:MPohoreski@...] Sent: Friday, October 05, 2001 3:43 PM To: GDAlgorithms-list@... Subject: RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) Yeah, I don't get why people tend to overly complicate things either. *cough due-to-false-sense-of-job-security? cough* I agree, the notation can get in the way at times. There is something to be said for conciseness and compactness, but not at the cost of obfuscation !! Notice the parallel to programming. ;-) At least I'm not put off by the notation as I used to be. Sometimes I wonder if mathematicians use so many foreign glyphs because they can. ;-) I'm finding that if one can understand the terminology, the notation isn't as bad. i.e. orthogonal-orthonormal basis what? ;-) I'm just glad we don't have to deal with super & sub scripts in code :) "But teacher, it's all Greek!" "Well, you'd better learn to read Greek then!" ```

 Re: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Tom Hubina - 2001-10-06 00:17 ```At 04:59 PM 10/5/2001, Ron Levine wrote: >Brian Hook wrote: > > >..... Hell, vector > >notation frightened the hell out of me 10 years ago, and then someone > >explained what vectors and things like the dot and cross product were, > >and I was like "Oh, well crap, why didn't someone SAY so?!" > > > >They probably DID say so. At least _I_ said so when I was teaching >calculus. Maybe you were asleep in the back row. Or perhaps in the >student union playing video games? Don't need the derision there Ron. In any case, "No one can be _told_ what the Dot Product is. You have to see it for yourself". You can be told over and over again what the Cross and Dot products are, but until you have the opportunity to work with them you won't have that "ding" where you can visualize the operation in your head. In any case, I'd like to see this thread and the one about why math types don't write their papers in english to die. They never go anywhere useful and at worst get rather messy. Tom ```

 Re: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Ron Levine - 2001-10-06 00:49 ```Brian Hook wrote wrote: >I think most papers would be a lot more readable for non-math-stud >programmers if they just showed pseudocode instead of the math notation, Wrong >but that's selfish desire more than anything else. It's also a cheap >rationalization for my sucky math kung fu =) Correct. And Jason Dorie wrote > > .... Having very little formal >math background, I have difficulty with mathematical notation and language, >but grasp complex concepts easily when they're put into english or code. > A fallacy. Anyone who thinks that mathematical relationships are more clearly expressed in code, or in words, without the efficient symbolism that mathematicians have worked out, is whistling in the dark. Mathematical notations are not due to the innate perversity of mathematicians, but rather to long evolution and struggle to find the clearest means of presenting certain classes of abstractions and the complex relations among them. Code has its purposes and mathematical notations have theirs. Just as different code languages have their areas of applicability (certain operations are much more clearly and concisely expressed in Perl than in C, and Perl looks at first like Greek to the student trained in C), there is a domain of discourse for which the mathematical notations that have evolved are most suitable. If you want access to the math, then you ought to learn the language. Just as you wonderfully expand your mind by learning more than one natural language, enhance your employability by learning several programming languages, your ability and efficiency in making use of mathematical knowledge in your work benefit immeasurably from taking the trouble to learn the language. Throwing up your hands and proclaiming, almost proudly, that you are a "programming stud" who sucks at math, and that's that, just doesn't cut it. Ron ```

 Re: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Ron Levine - 2001-10-06 00:52 ```Tom Hubina wrote: >At 04:59 PM 10/5/2001, Ron Levine wrote: >>Brian Hook wrote: >> >> >..... Hell, vector >> >notation frightened the hell out of me 10 years ago, and then someone >> >explained what vectors and things like the dot and cross product were, >> >and I was like "Oh, well crap, why didn't someone SAY so?!" >> > >> >>They probably DID say so. At least _I_ said so when I was teaching >>calculus. Maybe you were asleep in the back row. Or perhaps in the >>student union playing video games? > >Don't need the derision there Ron. > Umm, sorry for leaving off the smiley. 'Twas meant in good natured jest (and to keep it on the topic of game) . I do have the highest respect for Brian's talent and contribution. Ron ```

 Re: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Peter Dimov - 2001-10-06 12:56 ```From: "Brian Hook" > I think most papers would be a lot more readable for non-math-stud > programmers if they just showed pseudocode instead of the math notation, > but that's selfish desire more than anything else. It's also a cheap > rationalization for my sucky math kung fu =) Most algorithms would probably be much more readable for non-programmer mathematicians if they just used the familiar sigma instead of strange for loop constructs. :-) -- Peter Dimov Multi Media Ltd. ```

 Re: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Peter Dimov - 2001-10-06 13:00 ```From: "Jason Dorie" > As for Ron's coordinate space example, I have an easier time digesting > ScreenPos, WorldPos, and ClipPos than (x,y,z), (x',y',z') and (x^,y^,z^) or > the like. To me, when reading > -1 T > (x',y',z') = (x,y,z) * V[T] * T [C] * (x^,y^,z^) > > the purpose would be clearer if written > > ScreenPos = WorldPos * View * CamTranspose * ClipTranspose Absolutely right. But try to actually work (on paper) with these names - they'll quickly degrade to Ps = Pw * V * Ct * Lt. Mathematicians spend a lot of their time writing; hence the short and concise notation. -- Peter Dimov Multi Media Ltd. ```

 RE: [Algorithms] Ofuscation (was Bug in published gluQuat routines) From: Jason Mitchell (ATI Technologies) - 2001-10-08 16:09 ```Jay wrote: > In short, it sounds like you're saying that the size of the > readership and their convenience is unimportant when deciding=20 > how to publish mathematical information. It's a good thing=20 > you aren't trying to sell those papers ;-) Well put. We spent a lot of our editing time on "Curved PN Triangles" (aka TRUFORM aka N-Patches) catering to two totally different audiences. Jorg is used to writing for a very academic audience, but Alex, Chas and I tend to hang out with guys like you find on this list. There was a lot of "but it SAYS that already," followed up with "but it's not OBVIOUS that that's what we mean....we don't want to have to write this paper TWICE." (Conversely, Alex, Chas and I tended to fall short on rigor in the writing and Jorg fixed that up big time.) Our argument for clarity was that the academics wouldn't mind what amounted to an extra couple of paragraphs in the paper, but the pragmatic game developers would mind it NOT being there. And after Randy Pausch's (of the ALICE project at CMU) comments during a round table at I3D 99 that the academic community could learn from the exposition found in Game Developer Magazine, I felt we were justified in making the article more user friendly. But be careful when performing this balancing act; my impression of some of the comments received from the reviewers was that they were clearly biased against the pragmatic tone of the paper. -JasonM ```