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tef
May 30, 2004

-> some l-system crap ->

Hard NOP Life posted:

How can you put all the integers in a list in the first place if its infinite? I know this is a numbershit 101 for you guys but this just doesn't seem intuitive at all to me

i can write a program that prints them out in order, one by one. (assuming bignums :3 )

it might not ever finish, but I can given a number, tell you it's position.

putting in a list, i mean, making an ordered sequence.

tef fucked around with this message at 04:52 on Feb 11, 2013

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PENETRATION TESTS
Dec 26, 2011

built upon dope and vice
this is all about relative sizes of infinite sets so "doesn't seem intuitive at all" is about right

FamDav
Mar 29, 2008
the rationals are a bit funky but if you visualize the top right of the coordinate plane and then make a zig zag motion through it you can see how it works. let me see if i can find a picture

tef
May 30, 2004

-> some l-system crap ->

FamDav posted:

the rationals are a bit funky but if you visualize the top right of the coordinate plane and then make a zig zag motion through it you can see how it works. let me see if i can find a picture



calkin wilf sequence is my favourite mapping, as mentioned earlier.

tef
May 30, 2004

-> some l-system crap ->


:2bong:

Phobeste
Apr 9, 2006

never, like, count out Touchdown Tom, man
dad, stop

please, dad

Nevergirls
Jul 4, 2004

It's not right living this way, not letting others know what's true and what's false.
all this maths talk reminds me of reading gödel escher bach in high school

unsure if that permanently expanded or permanently damaged my mind

tef
May 30, 2004

-> some l-system crap ->
go to your room and don't come back downstairs until you've written down a(4,4)

tef
May 30, 2004

-> some l-system crap ->

Nevergirls posted:

all this maths talk reminds me of reading gödel escher bach in high school

unsure if that permanently expanded or permanently damaged my mind

given it wasn't martin gardner i'd opt for the latter

skeevy achievements
Feb 25, 2008

by merry exmarx
fond memories of big rudin in grad school

sorry I mean the opposite of fond

hostile

FamDav
Mar 29, 2008

Internaut! posted:

fond memories of big rudin in grad school

sorry I mean the opposite of fond

hostile

http://www.okcupid.com/match?keywords=Big%20Rudin&only_text=1

its like the 6th entry on google for big rudin

Gazpacho
Jun 18, 2004

by Fluffdaddy
Slippery Tilde

tef posted:

given it wasn't martin gardner i'd opt for the latter
i'm a programmer today because of martin gardner

bastard

Symbolic Butt
Mar 22, 2009

(_!_)
Buglord

tef posted:

yes.

the natural numbers, the integers, the algebraic numbers and the computable numbers are countable.

when you take that all away, you're left with transcendental numbers. iirc.

and you can't put them in a list

not really, I mean, there are transcedental numbers like e and pi who are also computable numbers. the uncountable part of the real numbers is the weird infinite tricky poo poo

Symbolic Butt
Mar 22, 2009

(_!_)
Buglord
yospos needs a maths thread for discussions about how cool grigori perelman is

Cocoa Crispies
Jul 20, 2001

Vehicular Manslaughter!

Pillbug

Symbolic Butt posted:

yospos needs a maths thread for discussions about how cool grigori perelman is



here is fine, it's a nice change from people in denial about how bad c-languages and j-languages are

Blotto Skorzany
Nov 7, 2008

He's a PSoC, loose and runnin'
came the whisper from each lip
And he's here to do some business with
the bad ADC on his chip
bad ADC on his chiiiiip

yaoi prophet posted:

(also like famdav said 'truth' of an axiom is kind of a weird thing to talk about)

yes, and yet some putative axioms are clearly impossible to square with other axioms

going a level of abstraction above mathematics, it is clear that you can't have a logical system wherein the Axiom of Non-contradiction and some putative Axiom of Sometimes-Contradiction both exist. we call things axioms when we believe them this *holds hands far apart* much and can't prove them, and assert that they cannot be disproven inasmuch as no other axioms contradict them :ironicat:; there are plenty of mathematicians who either think aoc is a Lie, or only believe it this much *holds hands somewhat closer together*; calling it or any other thing that not everyone in the field believes an axiom is really an act of intellectual violence

Necc0
Jun 30, 2005

by exmarx
Broken Cake

gently caress you i need to go to bed

Jonny 290
May 5, 2005



[ASK] me about OS/2 Warp
i love math stuff but gently caress how do you educate yourself in math

im reading up on matrices lately because i discovered PDL and want to do stupid poo poo with it.

Deacon of Delicious
Aug 20, 2007

I bet the twist ending is Dracula's dick-babies

Jonny 290 posted:

i love math stuff but gently caress how do you educate yourself in math

poo poo, good luck

i'm getting educated in math right now and the book is only moderately helpful. everything useful comes from the prof, or from other students in the math center

Progressive JPEG
Feb 19, 2003

Sniep posted:

a massive attack album

FamDav
Mar 29, 2008

Otto Skorzeny posted:

yes, and yet some putative axioms are clearly impossible to square with other axioms

going a level of abstraction above mathematics, it is clear that you can't have a logical system wherein the Axiom of Non-contradiction and some putative Axiom of Sometimes-Contradiction both exist. we call things axioms when we believe them this *holds hands far apart* much and can't prove them, and assert that they cannot be disproven inasmuch as no other axioms contradict them :ironicat:; there are plenty of mathematicians who either think aoc is a Lie, or only believe it this much *holds hands somewhat closer together*; calling it or any other thing that not everyone in the field believes an axiom is really an act of intellectual violence

i think you're putting too much into the word axiom. while you are absolutely correct about the acceptance of zfc -- though the gross majority of mathematics do accept it and i dont why you call it an outright lie like you did -- that doesnt mean that it isnt an axiom as stated. it is a premise of a particular formulation of set theory, and you have the joy or lack thereof to work within the axioms of that particular formulation. In much the same way, you have the freedom to include the parallel postulate in your formulation of geometry or you don't.

In short, axioms are not always putative and they dont have to be

ps which putative axiom are you suggesting contradicts the axiom of choice?

Pardot
Jul 25, 2001




FamDav posted:


ps which putative axiom are you suggesting contradicts the axiom of choice?

axiom of omakase

Ericadia
Oct 31, 2007

Not A Unicorn

Jonny 290 posted:

i love math stuff but gently caress how do you educate yourself in math

im reading up on matrices lately because i discovered PDL and want to do stupid poo poo with it.

Get a textbook. Read and be bewildered by a chapter, then look it up on purplemath.com etc, then do the chapter exercises. P much the experience of a lot of college math students right there.

PrBacterio
Jul 19, 2000

FamDav posted:

ps which putative axiom are you suggesting contradicts the axiom of choice?
When I was in college I once wrote a paper about an interesting one, postulating a generalisation of Zermelo's theorem to infinite games, i.e. it stated that there exist a winning strategy for all perfect-information two-player games, not just finite ones, as an axiom. This has a number of interesting consequences, for example one theorem that can be derived in ZFS with this axiom is that all subsets of R are Lebesgue measurable, which in turn proves this axiom to be in contradiction to the AC (because the AC implies that there are non-Lebesgue-measurable sets).

FamDav
Mar 29, 2008

PrBacterio posted:

When I was in college I once wrote a paper about an interesting one, postulating a generalisation of Zermelo's theorem to infinite games, i.e. it stated that there exist a winning strategy for all perfect-information two-player games, not just finite ones, as an axiom. This has a number of interesting consequences, for example one theorem that can be derived in ZFS with this axiom is that all subsets of R are Lebesgue measurable, which in turn proves this axiom to be in contradiction to the AC (because the AC implies that there are non-Lebesgue-measurable sets).


so this is the axiom of determinacy, which is p cool and yields interesting results but is not a universally accepted axiom of set theory. its kind of contrived though.

what im really looking for is him to say nothing because ZF is logically independent of AC.

FamDav fucked around with this message at 09:54 on Feb 11, 2013

tef
May 30, 2004

-> some l-system crap ->

Jonny 290 posted:

i love math stuff but gently caress how do you educate yourself in math

im reading up on matrices lately because i discovered PDL and want to do stupid poo poo with it.

read a martin gardner book.

http://www.amazon.com/Colossal-Book-Mathematics-Paradoxes-Problems/dp/0393020231

tef
May 30, 2004

-> some l-system crap ->

FamDav posted:

what im really looking for is him to say nothing because ZF is logically independent of AC.

what's yellow and pro choice?


zorn's lemon

Catalyst-proof
May 11, 2011

better waste some time with you

tef posted:

read a martin gardner book.

qntm
Jun 17, 2009
just drop the axiom of infinity and become a strict finitist

Blotto Skorzany
Nov 7, 2008

He's a PSoC, loose and runnin'
came the whisper from each lip
And he's here to do some business with
the bad ADC on his chip
bad ADC on his chiiiiip

FamDav posted:

ps which putative axiom are you suggesting contradicts the axiom of choice?

AD is incompatible with it. it would be cool if true sort of like supersymmetry or OMG STRINGS in physics

skeevy achievements
Feb 25, 2008

by merry exmarx

Jonny 290 posted:

i love math stuff but gently caress how do you educate yourself in math

im reading up on matrices lately because i discovered PDL and want to do stupid poo poo with it.

same way a math student does, get some textbooks, start reading and most importantly, do the exercises

linear algebra (matrix poo poo) is a great way to start as the concepts are much simpler than say vector calculus (imo), the mechanics are pretty straightforward and lend themselves very well to solution by computer, it's very practical in a lot of computery applications, and it's the foundation of quantum mechanics which is another cool thing to learn about but you won't be able to measure anything without knowing how hermitian operators work on state vector inner products in hilbert space

not sure where your math's at right now but strang made a decent intro to linear algebra book

Blotto Skorzany
Nov 7, 2008

He's a PSoC, loose and runnin'
came the whisper from each lip
And he's here to do some business with
the bad ADC on his chip
bad ADC on his chiiiiip
you can never have enough linal, you can never have too good of a feel for diffeqs (esp if you dabble in electronics like johnny and want to jump back and forth between the time domain, frequency domain, and simple but 'weird' stuff like the s and z planes that are really frequency but retain information about transients)

Jonny 290
May 5, 2005



[ASK] me about OS/2 Warp
otto sniffed me out, i want to eventually do the electronics math.

im going to go back over a linear book as that's probably about where i need to restart

i got 36 math ACT blah blah could integrate and derive like a motherfucker, but that was like 4 presidential terms ago. been a minute

prefect
Sep 11, 2001

No one, Woodhouse.
No one.




Dead Man’s Band

this should have a sign on it that says "you must be this smart to post in this thread". :saddowns:

*posts anyway*

Jonny 290
May 5, 2005



[ASK] me about OS/2 Warp
also graph theory interests me too, i read up on that a little bit the other day

Quebec Bagnet
Apr 28, 2009

mess with the honk
you get the bonk
Lipstick Apathy

Jonny 290 posted:

also graph theory interests me too, i read up on that a little bit the other day

theory of lovely beep-boop music

FamDav
Mar 29, 2008

Otto Skorzeny posted:

AD is incompatible with it. it would be cool if true sort of like supersymmetry or OMG STRINGS in physics

like i said bruh bruh, ad is not a putative axiom and its p contrived as part of set theory. i'd rather have every vector space has a basis than some nonse about games having solutions.

Jonny 290 posted:

also graph theory interests me too, i read up on that a little bit the other day

graph theory is p cool and a lot of it is fairly intuitive.

this is a p good book but kinda expensive so maybe find a library or something?

FamDav
Mar 29, 2008
also real talk after you know a lot about linalg pick up a book on abstract algebra then buy a book on matrix groups and go h.a.m.

Blotto Skorzany
Nov 7, 2008

He's a PSoC, loose and runnin'
came the whisper from each lip
And he's here to do some business with
the bad ADC on his chip
bad ADC on his chiiiiip

FamDav posted:

like i said bruh bruh, ad is not a putative axiom

hence the 'axiom' part of the name :rolleye:




FamDav posted:

graph theory is p cool

you can make any (cs) problem a graph problem if you squint a little :hellyeah:

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FamDav
Mar 29, 2008

Otto Skorzeny posted:

hence the 'axiom' part of the name :rolleye:

now i seriously have no idea what you were and are getting at, besides your weird idea of truth.

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