UmbralRaptor changed the topic of #kspacademia to: https://gist.github.com/pdn4kd/164b9b85435d87afbec0c3a7e69d3e6d | Dogs are cats. Spiders are cat interferometers. | Космизм сегодня! | Document well, for tomorrow you may get mauled by a ネコバス. | <UmbralRaptor> … one of the other grad students just compared me to nomal O_o | <ferram4> I shall beat my problems to death with an engineer.
<bofh>
23:44:34 * Qboid gives egg a Teller-Ulam glaive
<bofh>
what about a Teller-Ulam glaive-guisarme-glaive?
<kmath>
<Newpa_Hasai> @McNutcase I'm bothered by the assumptions it makes about keyboards. (I typically have 0 to 5) Using the first, I g… https://t.co/THo9WCxC9Z
<egg|cell|egg>
I get My kink is trying to describe the cat that looks like anbocat
* UmbralRaptor
blinks.
<UmbralRaptor>
Oh.
<UmbralRaptor>
Somehow that's not surprising.
<egg|cell|egg>
Hah
<UmbralRaptor>
Relatedly, over half of @fioraaeterna's followers are or want to be catgirls.
<egg|cell|egg>
My 24 μm Spitzer keyboard has shipped
<egg|cell|egg>
Autosuggestion from keyboards: Keyboards and mice and men and women who are crazy busy with a question about a dozen of the day of the day but me pokes UmbralRaptor with a question of wording too on the wait no I don't technically have a cat with a question of wording
<egg|cell|egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a life
<egg|cell|egg>
Uh
<UmbralRaptor>
...what am I supposed to do with that strange thing?
<egg|cell|egg>
!Wpn UmbralRaptor
* Qboid
gives UmbralRaptor a stern warhead
<UmbralRaptor>
!wpn egg|cell|egg
* Qboid
gives egg|cell|egg a [DATA EXPUNGED] turnstile
<egg|cell|egg>
UmbralRaptor: kozai probably
<soundnfury>
aww man I did it again
<soundnfury>
I stayed up 'til nearly 4AM watching Jacob Rees-Mogg videos on YouTube.
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<soundnfury>
That's the second time in as many weeks :/
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<egg|work|egg>
!seen bofh
<Qboid>
egg|work|egg: I last saw bofh on [04.05.2017 00:07:49] in #kspacademia saying: "what about a Teller-Ulam glaive-guisarme-glaive?"
<egg|work|egg>
!wa CDT
<Qboid>
egg|work|egg: Central Time (Mexico) | daylight saving time: 4:07:12 am CDT | Thursday, May 4, 2017
* egg|work|egg
vaguely wondering what to make of condition numbers; if I understand things correctly, for large K, computing something with condition K and shoving that into something with condition 1/K should be ok, but the reverse is a terrible idea because the rounding error in the middle will be expanded to death by the second operation?
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<Iskierka>
... discovered a 3D printer in one of the uni labs. Not sure if can use
<Iskierka>
Says to speak with a person. May do if find a desired use
* whitequark
grumbles about keyboards
<whitequark>
i fucking hated the... whatever's the non-island style is called
<whitequark>
could as well try to type on wet pieces of soap
<whitequark>
Ellied: (computers being locked down) it's inevitable as long as you live somewhere the copyright cartel has enough power
<whitequark>
move to argentina or w/e
<whitequark>
or murder your government
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<egg|work|egg>
whitequark: what do you mean by island?
* egg|phone|egg
is in the tram, going home early because desk being moved
<egg|phone|egg>
My TL gets desk 39A
Thomas|AWAY is now known as Thomas
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* egg|zzz|egg
pokes bofh with a stick
<egg|zzz|egg>
!wpn whitequark
* Qboid
gives whitequark an orthogonal spear
<bofh>
egg|zzz|egg: ?
<bofh>
09:07:02 < egg|work|egg> !seen bofh
<bofh>
like was asking what you were poking me about :p
<egg|zzz|egg>
bofh: whether I was understanding how to use the condition properly
<egg|zzz|egg>
bofh: * egg|work|egg vaguely wondering what to make of condition numbers; if I understand things correctly, for large K, computing something with condition K and shoving that into something with condition 1/K should be ok, but the reverse is a terrible idea because the rounding error in the middle will be expanded to death by the second operation?
<egg|zzz|egg>
UmbralRaptor: hmm, so with a LEGO Saturn V, you only need to make a LEGO S-IB to also get the Saturn IB >_>
<kmath>
<TheRealDrMcCoy> @whitequark So VBA was right when it translated all tokens?
<whitequark>
egg|zzz|egg: I don't understand
<egg|zzz|egg>
whitequark: which makes sense; I learned VB6 and VB .net when I didn't know a word of english, and that didn't seem like an issue to me; I would probably have been awfully confused had the keywords been, say, in cyrillic
<egg|zzz|egg>
i.e., translating the tokens to french is probably not necessary; translating them to russian/chinese might be more useful
<egg|zzz|egg>
whitequark: also I think ALGOL 68 translated tokens too :-p
<whitequark>
oh, *script*
<whitequark>
nevermind I understood
<whitequark>
it's complex
<whitequark>
translating ocaml keywords to russian is not really feasible if you ask me
<egg|zzz|egg>
whitequark: yeah, the grammar probably makes things shitty, even to french
<egg|zzz|egg>
and then if you deal with libs written by other people, you *really* don't want to deal with identifiers in <insert language here>
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<egg|zzz|egg>
(though when I wrote VB 6/VB .net/even a bit of Ada 95 my identifiers were in french)
<egg|zzz|egg>
(which gets weird quickly, because the standard libs aren't)
<egg|zzz|egg>
!wpn regex
* Qboid
gives regex a Bekenstein Ꙭ with a LED attachment
<regex>
I read that as a "Beck CD" and got mad.
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<egg|zzz|egg>
!u Ꙭ
<Qboid>
U+A66C CYRILLIC CAPITAL LETTER DOUBLE MONOCULAR O (Ꙭ)
<egg|zzz|egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a prime falcon
<egg|zzz|egg>
UmbralRaptor: nomal|principia
<bofh>
egg|zzz|egg: yes
<bofh>
egg|zzz|egg: or at least there is a distinct possibility of rounding error blow-up. depends on how big K is and also other fun properties such as how sparse your matrices are etc.
<bofh>
!u ꙮ
<Qboid>
U+A66E CYRILLIC LETTER MULTIOCULAR O (ꙮ)
<bofh>
(I personally prefer "CYRILLIC LETTER SHOGGOTH" as a name for that one)
<whitequark>
lol
<egg|zzz|egg>
bofh: these aren't matrices
<egg|zzz|egg>
but it should apply to arbitrary functions
<egg|zzz|egg>
!wpn whitequark
* Qboid
gives whitequark a Kozai basilisk
<whitequark>
!wpn egg|zzz|egg
* Qboid
gives egg|zzz|egg an ordered inequality-like pentagon
<egg|zzz|egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a first/follow protractor
<egg|zzz|egg>
!wpn bofh
* Qboid
gives bofh a phosphorus Lovecraftian instability
<SnoopJeDi>
Perhaps a strange question, but are any of you perchance familiar with pyrography?
<egg|zzz|egg>
!wpn SnoopJeDi
* Qboid
gives SnoopJeDi an integrator
<egg|zzz|egg>
!wpn Iskierka
* Qboid
gives Iskierka a sub-calibre circle
<SnoopJeDi>
...an eleggant weapon, for a more civilized #kspacademia
<egg|zzz|egg>
do they tweet only a subset of the designs they ship?
UmbralRaptor is now known as NomalRaptor
<SnoopJeDi>
You could ask!
<egg|zzz|egg>
SnoopJeDi: eh, I know it has shipped, so I can just wait til the ninth :-p
<egg|zzz|egg>
NomalRaptor: nomal|principia
<egg|zzz|egg>
!choose nomal|principia
<Qboid>
egg|zzz|egg: Your options are: nomal, principia. My choice: principia
<NomalRaptor>
Pincipia
<egg|zzz|egg>
;choose nomal|principia
<kmath>
egg|zzz|egg: nomal
<SnoopJeDi>
oh neat, they sell just the keycap sets
<egg|zzz|egg>
yeah, in particular if your keycaps wear off they can reprint your design
<SnoopJeDi>
Neat!
<egg|zzz|egg>
NomalRaptor: pincipia?
Thomas is now known as Thomas|AWAY
<soundnfury>
egg|zzz|egg: it's for determining the orbital trajectories of PIN diodes, clearly
<bofh>
egg|zzz|egg: well, the analogy still holds. there's a possibility depending on how ill-behaved your functions are of blowup of rounding error, it may still be fine in some cases and not in others.
<egg|zzz|egg>
bofh: what do you mean by ill-behaved
<egg|zzz|egg>
besides the condition
<bofh>
basically that, since by "ill-behaved" I meant "output affected greatly by small perturbations in the input"
<bofh>
which I just realised is literally the definition of ill-conditioned.
<egg|zzz|egg>
bofh: pretty much, at least under assumptions of continuity & differentiability
<egg|zzz|egg>
bofh: well assuming that by ill-conditioned you mean "has a high condition number", and not a generic term of abuse
<egg|zzz|egg>
"The expression 'ill-conditioned'
<egg|zzz|egg>
is sometimes used merely as a term of abuse applicable to matrices or
<egg|zzz|egg>
equations, but it seems most often to carry a meaning somewhat similar
<egg|zzz|egg>
to that defined below."
<egg|zzz|egg>
(Turing, in Rounding-off errors in matrix processes)
<egg|zzz|egg>
bofh: so if your computation is ill-conditioned composed with well-conditioned, the order of composition matters greatly for the roundoff sensitivity then
<egg|zzz|egg>
thus if you can write f(x) = g1(h1(x)) = g2(h2(x)) with h1 and g2 being ill-conditioned (and the others well-conditioned in proportion, since the product of conditions is the condition of f), the h1->g1 computation is preferable
<egg|zzz|egg>
bofh: which is fun and not entirely intuitive :-p
<bofh>
Ahh. Yeah, that's correct AND unintuitive as shit.
<egg|zzz|egg>
bofh: indeed :D
<bofh>
nomal?
<bofh>
oh for fuck's sake irssi
<soundnfury>
!wpn bofh
* Qboid
gives bofh a Stern-Gerlach sum
<bofh>
it was up a page
<bofh>
ooh, handy :D
<bofh>
still want to see if I can DIY an atomic reference using Rb-87.
<soundnfury>
bofh: how do you anaesthetise a quantum mechanic?
<soundnfury>
... with |amine>
<soundnfury>
what does a quantum mechanic use to boil water?
<SnoopJeDi>
ow
<soundnfury>
... a |tle>
<egg|zzz|egg>
bofh: nomal?
<SnoopJeDi>
my reaction to these jokes: <vo|
<soundnfury>
other joke possibilities include |chup>, |one>, |cetera>
<soundnfury>
!wpn SnoopJeDi
* Qboid
gives SnoopJeDi a graphite phototransistor
<soundnfury>
(huh, that might actually be a thing)
<soundnfury>
(well, if you s/graphite/organic, but near enough)
<kmath>
<bofh453> @KardOnIce @cgranade I literally *NEVER* want to deal with insanity like this ever again: https://t.co/voGLZNAs01
<egg|zzz|egg>
bofh: so, concrete example, on [0, π/2], arc cos (cos x / 2) is a well-conditioned function. cos has infinite condition as x tends to π/2, so evaluating it as written should behave much better than as arc sin (sqrt(3 + sin^2 x) / 2), since sin has vanishing condition for right angles (and therefore the rest has infinite condition)...
<SnoopJeDi>
That's ugly even by F77 standards :|
<egg|zzz|egg>
why is that mixed case
<bofh>
I DON'T KNOW! LITERALLY EVERYTHING ABOUT IT IS AWFUL. Still only the second-most unreadable codebase I've dealt with.
<egg|zzz|egg>
bofh: also, I do use a lot of short equationlike identifiers, but only as locals
<egg|zzz|egg>
structure members and functions have verbose names
<egg|zzz|egg>
exceptions: π, e
<bofh>
So let's start with: - undocumented, - THAT MANY parameters
<bofh>
I still get nightmares from this pile of shitfuck.
<SnoopJeDi>
Oh Fortran...
<egg|zzz|egg>
bofh: ah, *now* that's FORTRAN
<egg|zzz|egg>
bofh: it uses the logical IF rather than the arithmetic one though, so at least you've got that going for you :-p
<bofh>
I don't think it's a "Fortran" issue so much as a "started out as ~40 year old Fortran w/most recent commit prior to me looking at it being >10 years ago"
<bofh>
egg|zzz|egg: hey I LIKE the arithmetic IF
<SnoopJeDi>
"Now That's What I Call(FORTRAN) 77" would be a good title for a blog post bemoaning aged scientific code
<bofh>
SnoopJeDi: OH GOD I SWEAR I ALREADY HAVE THAT WRITTEN IN ABOUT 40 IRC RANTS
<bofh>
at least it would be *minimal* effort to assemble
<egg|zzz|egg>
the first & second column being the calculator display when programming
<egg|zzz|egg>
(one line at a time)
<egg|zzz|egg>
that's a fairly short program, when it gets too long you have to factor madly and add jumps everywhere to make it fit into one side of a tape
<egg|zzz|egg>
right, so 224 instructions, but 112 per card side only
<egg|zzz|egg>
also the program counter loops, so it's tricky to fill all 224
<egg|zzz|egg>
otoh if you use 112 instructions you can take advantage of the Run/Stop in instruction 113 (uninitialized program memory is full of R/S), so no looping issues
<egg|zzz|egg>
!wpn NomalRaptor
* Qboid
gives NomalRaptor a gaseous infimum
<NomalRaptor>
!wpn egg|zzz|egg
* Qboid
gives egg|zzz|egg a submillimeter gallium photodiode
<bofh>
egg|zzz|egg: oh good god
<egg|zzz|egg>
NomalRaptor: nomal|zzz
<egg|zzz|egg>
!choose nomal|zzz
<Qboid>
egg|zzz|egg: Your options are: nomal, zzz. My choice: zzz
<egg|zzz|egg>
;choose nomal|zzz
<kmath>
egg|zzz|egg: nomal
<egg|zzz|egg>
bofh: :D
<NomalRaptor>
egg|zzz|egg: I choose: Nomal
<Iskierka>
;choose egg|zzz|egg
<kmath>
Iskierka: egg
<egg|zzz|egg>
bofh: eh, there's sillier: the HP-35C (not programmable) needed extra memory to compute trig functions, so it would clear the top of the stack
<NomalRaptor>
o_O
<bofh>
egg|zzz|egg: the hell?
<egg|zzz|egg>
(those calculators have a 4 element stack, x, y, z, t; computing a trig line would zero t because it was used as a register for the calculation)
<egg|zzz|egg>
bofh: the 35-C was notoriously shit at trig, then they got Kahan to do the numerics
<egg|zzz|egg>
so the HP 67 is really good at it
<egg|zzz|egg>
does the argument reduction right and all that
<bofh>
oh god of course he would do things correctly
<egg|zzz|egg>
(which means that it's better than x87 fcos/fsin, since those give up on argument reduction eventually)
<egg|zzz|egg>
(you should never use fcos fsin directly of course, you should call a library that does the payne-hanek)
<bofh>
oh of course someone's ported $CALCULATOR_EMULATOR to JS
<egg|zzz|egg>
bofh: switch it to W/PRGM and behold the magnificent program editor
<egg|zzz|egg>
(you navigate it with SST, [h] BST, and GTO . ###)
<egg|zzz|egg>
[h] DEL removes an instruction (probably pads with a R/S at the end or something), and if you want to navigate to a label you can go back to RUN mode, run GTO (your label), and that will put the program pointer there
<egg|zzz|egg>
(of course it will navigate to the next label with that number/letter, if you have multiple instances of that label things get tricky)
<egg|zzz|egg>
you have a call stack! of depth 3
<egg|zzz|egg>
25 registers
<egg|zzz|egg>
addressable by the value in the 25th register (I)
<egg|zzz|egg>
wait no 26
<egg|zzz|egg>
or directly for 0 .. 9 and A .. E and I
<egg|zzz|egg>
10 .. 19 can be swapped with 0 .. 9 with P<>S
<egg|zzz|egg>
20 different labels
<egg|zzz|egg>
a stack of size 4
<egg|zzz|egg>
*and a flag!*
<egg|zzz|egg>
see the shifted commands for the +-*/ keys, those are flag-related operations
<egg|zzz|egg>
where F? is a conditional skip probably
<egg|zzz|egg>
there's also ISZ, DSZ, ISZ(i), DSZ(i), which are (in|de)crement and skip if zero, either on register i, or on the register whose number is the value of i