18:42 < iceweaselOS> Humphrey the rabbit does not work :(
18:42 < iceweaselOS> it gets stuck in pause
+--- Day changed Thu Sep 11 2014
+10:53 < matches> I wonder who that was
+10:59 < matches> "... for some reason in irram they decided to let x<y loop forever if x=y ..."
+10:59 < matches> That's...
+10:59 < matches> Ok
+10:59 < matches> Fine
+11:00 < matches> sulix: How many "x < y" checks do we have?
+11:10 < sulix> A finite number..., I guess?
+11:10 < matches> iRRAM appears to do some sort of fancy wrapping of MPFR
+11:11 < matches> So I'm not hopeful
+11:11 < matches> Considering MPFR seems to slow down hideously
+11:11 < sulix> Wrap all of the numbers inside other numbers.
+11:11 < matches> I did some more ParanoidNumber stuff
+11:11 < matches> Maybe one day it will actually give the correct result
+11:11 < matches> Then I can actually implement Simplify() ...
+11:12 < sulix> http://en.wikipedia.org/wiki/Binary_GCD_algorithm
+11:12 < sulix> (If you want fast gcd for bigints, btw)
+11:14 < matches> Should I plead "I had assignments due" or "I was seeing if Humphrey The Rabbit would work on a Firefox OS phone" in the progress meeting...
+11:14 < matches> iRRAM does seem to have a friendly install script
+11:15 < sulix> As long as you don't plead the FITH, you're probably fine. :P
+11:16 < matches> I'm fairly certain that floats are the best possible number representation and you need to do something more clever than just change your number representation if you want an arbitrary precision document
+11:16 < matches> Something like... some kind of... quad... tree
+11:17 < sulix> Do not use those words. You may not be able to vanquish what you summon.
+11:23 < matches> I need to write an abstract...
+11:24 < matches> "We compare different number representations and find them all to be useless"
+11:24 < matches> Hmm, something non commital
+11:25 < matches> "By the date of this conference we will hopefully have something interesting to say"
+11:25 < matches> "We discuss the drawbacks of adding IRC channel logs to git repositories"
+11:26 < matches> Ah nooo
+11:26 < matches> iRRAM uses "REAL"
+11:28 < matches> Also someone's been using too much javascript because there are all these extra ';' in their headers and it annoys -Werror=pedantic
+11:58 < sulix> ... :-(
+15:04 < matches> Spot the slight mathematical flaw in iRRAM
+15:04 < matches> inline LAZY_BOOLEAN operator == (const REAL& x, const REAL& y){ return (y<x)&&(x<y) ; }
+15:05 < matches> inline LAZY_BOOLEAN operator != (const REAL& x, const REAL& y){ return (y<x)||(x<y) ;}
+15:06 < matches> inline LAZY_BOOLEAN operator <= (const REAL& x, const REAL& y){ return (x<y); }
+15:06 < matches> They don't seem to have equality
+15:06 < matches> But that doesn't stop them implementing the operators...
+18:21 < sulix> Clearly the way to fix your computer's clock issues: http://jackf.net/bezier-clock/
+18:22 < matches> Against all better judgement I am still trying to fix ParanoidNumber
+18:22 < matches> And oh my goodness that is amazing
+18:23 < matches> But
+18:23 < matches> It still thinks it's 02:23:31
+18:23 < sulix> Unless I fix the quadtree view code, infinite precision only works if the coordinate you're zooming in on can _not_ be represented as a float.
+18:24 < matches> ?
+18:24 < matches> ??
+18:25 < sulix> So if you zoom in on a coordinate that is exactly representable as a sum of powers of two, then you're always zooming in on the boundary between two quadtree nodes.
+18:25 < matches> Haha
+18:26 < matches> Could you use an extra "centre" node?
+18:26 < matches> That would be redundant though
+18:26 < matches> Hm
+18:26 < sulix> Nah, I just need to actually get around to supporting displaying content from more than one node at a time.
+18:32 < matches> ParanoidNumbers seem to actually construct properly now
+18:32 < matches> At least, if you construct them and convert back to doubles, they are within 5% of the double
+18:33 < matches> Now... simplifying...
+18:33 < sulix> With float ParanoidNumbers or double ParanoidNumbers?
+18:33 < matches> doubles
+18:33 < matches> But I'm testing the traversal of the list(s) when converting back
+18:34 < sulix> Ahhh...
+18:34 < matches> You need two recursive functions and I really hope I don't get stack overflows...
+18:35 < matches> You start with "value = Head.value * Head.MultiplyFactors + Head.AddTerms"
+18:35 < matches> Then define MultiplyFactors as "1 * f1.AddTerms * f2.AddTerms * ..."
+18:36 < matches> Then AddTerms is "0 + t1.MultiplyFactors + t2.MultiplyFactors + ..."
+18:36 < matches> It gets confusing how you deal with division and subtraction...
+18:37 < matches> I'm sure you can write that as a non recursive function... somehow...
+18:37 < matches> I don't seem to be overflowing the stack though
+18:38 < matches> So 666 operations have taken 5 minutes
+18:38 < matches> But that's without simplifying anything
+18:38 * sulix is currently traversing quadtree nodes via needlessly complicated recusion.
+18:38 < matches> I am quitely confident that I may be able to render a frame in at most 10 years
+18:39 < sulix> Clearly in your seminar, you should start zooming in and when it gets slow just say "If you'll bear with me for a moment" and then just leave the room.
+18:39 < matches> The thought has crossed my mind...
+18:41 < matches> Something that is kind of cool is I can change the digit to be something like uint8_t and see how well it converts to floats
+18:41 < sulix> That is pretty cool.
+18:41 < matches> It will be when I implement it that is
+18:41 < sulix> How well _does_ it convert to floats?
+18:42 < sulix> (Also, sudden thought: is NaN a valid mark for this project, as I am getting the feeling it should be...)
+18:42 < matches> My paranoid number tester does occasionally fail with "NaN != NaN"
+18:42 < matches> That's good!
+18:42 < matches> They both got NaN!
+18:43 < matches> Well, ideally I will be able to make it so that the ParanoidNumber *doesn't* get NaN
+19:17 < sulix> Hmm... I think the ext4 driver just crashed on my computer.
+19:18 < matches> :S
+19:18 < sulix> I didn't know that was possible.
+19:25 * sulix -> other computer
+19:31 < matches> I'm inventing cool terminology
+19:31 < matches> Paranoia
+19:31 < matches> Is the number of ParanoidNumbers...
+19:33 < sulix> "Peeking around corners looking for NaNs, wearing a tinfoil hat to guard against surious SIGFPEs, it's... ParanoidNumber!"
+19:33 < matches> That is the best description
+19:33 < matches> Well
+19:34 < matches> It actually kind of blindly walks around the corner into the SIGFPE and then freaks out and runs back around it
+19:35 < sulix> It's like running away from the fireball in slow motion.
+19:37 < matches> I'll at least win an award for most original number representation
+19:37 < matches> (He hopes)
+19:37 < matches> (It's probably not)
+19:38 < matches> (It's probably equivelant to one of the many alternative number representations that I didn't look up...)
+19:38 * sulix also hopes there is an award for most buggy implemention of a quadtree.
+19:38 < matches> (Specifically, the ones in the Handbook of Floating Point arithmetic that were described as "curiously useless")
+19:40 < sulix> (Googling "curiously useless" yields the phrase: "My boss is curiously useless. He fanatically creates an abundant amount of work for everyone while at the same time manages to get nothing done.")
+19:40 < sulix> (I suspect they're referring to iRRAM)
+19:40 < matches> Bahaha
+19:43 < matches> I think that simply replacing floats with int8_t actually does work
+19:44 < matches> Which is cool because it is easier to test if an operation with int8_t can be represented exactly
+19:44 < matches> But on the other hand there will be fewer operations that can be represented exactly
+19:45 < matches> I think this may actually work
+19:46 < matches> You don't need arbitrary precision to represent screen space and you are converting from view space to screen space
+19:47 < matches> So maybe it won't be that terrible, even though it would need a lot more digits to represent the same arbitrary precision value
+19:47 < matches> I think
+19:47 < sulix> You need more than an int8_t to represent screen space.
+19:47 < sulix> (An int16_t would do it, though)
+19:48 < matches> You just need to be able to represent each individual factor in the operation
+19:48 < matches> factor and term
+19:48 < sulix> You may (probably will) need factors > 127
+19:48 < matches> Probably
+19:50 < matches> If I just implement an "Exact" template function...
+19:50 < matches> Uh oh, templates
+19:51 * sulix thinks that he's approaching the worst recursive subroutine ever written.
+19:52 < sulix> (It has four switch statements in it so far)
+19:57 < matches> Template errors
+19:57 < matches> Aargahasdf
+19:58 < matches> Compilers are so good at identifying exactly what error you made and so useless at actually providing any hint of how you can fix it
+19:58 < matches> It's totally different from like "expected ';' before ..."
+19:59 < sulix> I saw a feature request for Google translate to support "gcc -> English".
+19:59 < matches> I want to specialise some template static member functions...
+19:59 < matches> That was my first mistake...
+20:00 < matches> Ok, they don't need to be static member functions, they can just be ... whatever you call a function that has no namespace associated with it
+20:01 < sulix> Functions...?
+20:01 < matches> Bah
+20:01 < matches> I would say "Regular functions" but they tend to be less common in C++
+20:02 < sulix> I've heard them called "first-class functions" before.
+20:03 < matches> That's a little elitist
+20:03 < sulix> I'm sort-of enamoured with the idea of "business-class functions" and "economy-class functions," though.
+20:11 < sulix> BTW, I just commited something that doesn't compile. Fixes will come shortly, it was just the easiest way to get it from computer A -> computer B.
+20:13 * sulix has made a typo and copy-pasted it into 16 places.
+20:13 < matches> copy-paste is best practice...
+20:14 < matches> It irks me that "a -= b" is equivelant to "a += (-b)" but there is no "a /= b == a *= (-b)"
+20:14 < matches> Well there is sort of, but only for rationals
+20:14 < sulix> The operator you're looking for is (1 / b)
+20:14 < matches> Yes, but - is quicker
+20:14 < sulix> This is true.
+20:15 < matches> I mean 3 can be represented exactly but 1/3 cannot
+20:15 < matches> With floats
+20:15 < matches> Most annoying
+20:15 < matches> I'm currently trying to reduce all the superflous "{0 + ...}" in ParanoidNumber
+20:16 < matches> It likes to create 1000 element lists with 900 zeroes in a row
+20:35 < unmercifulfish> this is gripping reading
+20:35 < unmercifulfish> so glad I am a part of this
+20:35 < matches> This is the cutting edge of useless research
+20:41 < sulix> "The bézier tiptoed out of bed. What an adventure it would be to go beyond the quadtree node in which it had lived its entire life. Its mother had told it sternly that it was dangerous to wander the dark wastes beyond the root node. Bobby Bézier had never believed the stories, though: there were no such things as wild NaNs that ate all of the coefficients of naughty boys. Bobby looked up at the sky: the infinite void of night penetrated only by the deb
+20:43 < Pommers> Oh yeah. One of the people in cs has a nice post on their door about rabbits that I want to grab a copy of
+20:50 < matches> I have a "TrustingOp" and "ParanoidOp"
+20:50 < matches> I think I'm having too much fun...
+20:54 * sulix has decided to give up actually coding and take up writing bézier curve fanfiction full time.
+20:55 < sulix> (People say it's derivative, but it's just about to reach a turning point)
+21:15 < unmercifulfish> qdb
+23:09 < matches> Oh dear
+23:09 * matches curses kahan
+23:10 < matches> I do not understand how this works, but if I delete terms that are "-0" things break
+23:13 < matches> So I got to the point where ParanoidNumber gave results that were reasonably close to just using a normal double without simplifying them
+23:14 < matches> And now I am basically adding random lines of code and running the tester and seeing if it still works :S
+--- Day changed Fri Sep 12 2014
+00:15 < matches> This reminds me of the James Micken comment about addition and multiplication basically being the same thing...
+01:19 < matches> Oh my goodness
+01:19 < matches> I think ParanoidNumber just worked for one very specific case!
+01:19 < matches> ParanoidNumber: 0.3 + 0.3 + 0.3 = 9/10, ToDouble() -> 0.9000000000000000222044604925031308084726
+01:20 < matches> double: 0.3 + 0.3 + 0.3 = 0.9000000000000001332267629550187848508358
+01:20 < matches> And strtod("0.9") = 0.9000000000000000222044604925031308084726
+01:23 < matches> For 0.2+0.2+0.3 = 7/10 it has an error of 1e-16 compared to doubles which apparently have no error
+01:24 < matches> But as floats it has an error of 1e-8 compared to 4e-8
+01:24 < matches> Hmm, why does 7.0 / 10.0 give a bigger error than 0.2 + 0.2 + 0.3
+01:24 < matches> Oh
+01:24 < matches> It'll be denormals probably
+01:25 < matches> That is... quiet irritating
+01:27 < matches> So... it is sometimes better than a float but only if there is a full moon and you sacrifice thrice the number of one tenth of unity goats three times
+01:28 < matches> The other times it breaks because subtraction is totally FITH
+01:29 < matches> Oh, it should be able to do 1/3 + 1/3 + 1/3 except my calculator tester doesn't allow me to enter non decimal numbers
+01:32 < matches> I think 0.3+0.3+0.3 is the only thing it can do better than regular floats
+01:32 < matches> Woo
+01:40 < matches> Ah it is better at beating doubles when it is using doubles as the digit type
+01:40 < matches> But it still is sometimes worse if you have a small number of operations
+01:40 < matches> Probably because one division is less precise than several additions
+01:42 < matches> I'm going to keep telling myself that this is useful
+01:42 < matches> After I sleep
+01:51 < Pommers> It isn't currently a full moon...
+01:51 < Pommers> Also
+01:51 < Pommers> Go to bed
+11:27 < matches> It was a full moon after I sacrificed the goats
+11:40 < Pommers> Stop toying with space matches
+--- Day changed Sat Sep 13 2014
+09:25 < unmercifulfish> I feel that the logs for this chat should just be added to qdb
+09:25 < unmercifulfish> < matches> It was a full moon after I sacrificed the goats
+12:36 < Pommers> Should make a QDB bot for submitting them
+16:20 < matches> When sulix is awarded the nobel prize for his work on quad trees, I will be proud to be a part of this channel
+16:21 < Pommers> Until then you won't be?
+16:23 < matches> I've been thinking of adding a "grep -v matches" before the automatic log commit
+17:45 < matches> I am a horrible person
+17:45 < matches> I am exploiting that "delete" acting on a NULL pointer has no effect
+17:46 < matches> "delete Operation(new ParanoidNumber(a), ADD)"
+17:47 < matches> Where Operation will either return the first argument or NULL
+17:50 < matches> At the moment I'm very pleased with how cleverly I am about to shoot myself in the foot
+17:50 < matches> We'll see how I feel after I pull the trigger
+17:53 < matches> I have either written an extremely elegant or an extremely segfaulting function
+17:57 < matches> The latter is looking more and more likely
+17:57 < matches> But I'm sure there is beauty underneath
+17:57 < matches> Like the ugly duckling!
+17:59 < matches> There's still hope, it turns out I'm segfaulting way before I even get to that
+18:01 < matches> Apparently 2+1 is 6, but doubles think 2+1 is 5
+18:02 < matches> "Freedom is the freedom to say 2+2=4, if that is granted, all else follows"
+18:06 < matches> Ok, 1 + 1 is 2
+18:06 < matches> I think we can call that a result
+18:06 < matches> Write the thesis and we're done here
+22:18 < matches> 1 + 0.3 = 13/10 and 13/10 + 0.2 = Segfault
+22:18 < matches> Getting close
+22:19 < matches> Now I'm doomed to not sleep until it works because I'm never going to remember how this works
+22:20 < Pommers> Got a whiteboard?
+22:20 < matches> I do actually but it's in the other room
+22:20 < matches> And it does not have space for this
+22:22 < matches> I don't think I've ever used so many delete operators...
+22:23 < matches> Also constructing a 4 diretional list on the stack then stealing one of the branches
+22:23 < matches> It's a game of "dodge the double delete!"
+22:24 < matches> Which reminds me, we have copious memory leaks in an external library
+22:24 < matches> 'ld' ?
+22:25 < matches> /lib/x86_64-linux-gnu/ld-2.19.so
+22:25 < matches> Not sure if that's something I'm doing wrong
+22:26 < matches> Turns out you can't pipe valgrind's output to less
+--- Day changed Sun Sep 14 2014
+18:23 < matches> http://szmoore.net/ipdf/sam/abstract.txt
+18:24 < matches> You know
+18:24 < matches> It sounds a lot more boring than it has been
+18:24 < matches> I also need a title
+18:24 < matches> "Number Representations and Precision in Vector Graphics" ?
+18:24 < matches> I'm too scared to pick something punny...
+18:26 < matches> Libreoffice thinks that is 147 words and pluma thinks it is 150...
+18:26 < matches> Oh
+18:26 < matches> hyphenated IEEE-754
+18:28 < matches> I think the first sentence could probably be less mind numbingly boring
+18:28 < matches> My last thesis started with "In this project" which seems terribly not academic
+18:29 < matches> (Every time I read that thesis I get a little more convinced that the markers didn't actually read any of it)
+18:29 < matches> ParanoidNumbers are not going well
+18:30 < matches> Like, it's hard to debug where things go wrong when you have a list like this:
+18:30 < matches> debug: main (tests/paranoidcalculator.cpp:75) - a is: {3*(23*(398123+(1/10+(2/100+(3/1000+(5/10000+(1/100000+(2/1e+06+(2/1e+07+(3/1e+08)))))))))+(3*(398123+(1/10+(2/100+(3/1000+(5/10000+(1/100000+(2/1e+06+(2/1e+07+(3/1e+08)))))))))/10+(4*(398123+(1/10+(2/100+(3/1000+(5/10000+(1/100000+(2/1e+06+(2/1e+07+(3/1e+08)))))))))/100+(1*(398123+(1/10+(2/100+(3/1000+(5/10000+(1/100000+(2/1e+06+(2/1e+07+(3/1e+08)))))))))/1000+(2*(398123+(1/10+(2/100+(3/1000+(5/10000+(1/100000+(2/1e+06+(2/1e+07+(3/1e+08)))))))))/10000+(3*(398123+(1/10+(2/100+(3/1000+(5/10000+(1/100000+(2/1e+06+(2/1e+07+(3/1e+08)))))))))/100000))))))/10+(1*(23*(398123+(1/10+(2/100+(3/1000+(5/10000+(1/100000+(2/1e+06+(2/1e+07+(3/1e+08)))))))))+(3*(398123+(1/10+(2/100+(3/1000+(5/10000+(1/1 ...
+18:31 < matches> That's without simplifying it
+18:31 < matches> But when it gives the wrong results before you even simplify it, that's bad
+18:32 < matches> I'm preeety sure it's not just giving the wrong results because it has a stupid number of terms/factors
+18:32 < matches> It's wrong enough that there's an extra factor or a factor missing or I don't even
+18:34 < matches> Hmm
+18:34 < matches> I want to add "Unlike paper, ..." before the third sentence
+18:34 < matches> I'm going to Captain Obvious
+18:38 < matches> :(
+18:38 < matches> Panic mode is well and truly activated now
git.ucc.asn.au / ipdf / documents.git / blobdiff
UCC git Repository :: git.ucc.asn.au