Mathematics - 2017-06-14 (page 2 of 9)

TheGreatDuck

5:00 AM

so... like for instance... pointers in game maker are broken

so i just took an array and shoved a memory allocator in it

Faust7

if a computer doesnt work i can fix it. if a program doesnt work i re-load it ;P

TheGreatDuck

now I have working 'pointers'

MarksCode

dont point, its rude :P

Faust7

lol

TheGreatDuck

@Faust7 if a program doesn't work I uninstall it. Unless it is my program... then I rebrand it as a feature.

otherwise, I pretty much expect it to not be working yet

Faust7

5:01 AM

omg what are you microsoft!

TheGreatDuck

(i mean, aside from the development phase)

in which case all hell can break lose

@Faust7 no. Microsoft can't program a lightbulb. Their own OS is so massive that standards on numbers of glitches predict so many security holes that you can drive a US army tank straight in.

Faust7

lol

there shit never works right

i only use microsoft for gaming

TheGreatDuck

think of this way

3 bugs per 1000 lines of code

windows has roughly a billion from what I've heard

do the math

granted, 3 is the maximum for basic stuff

but still

Faust7

which is why my computer dual boots ^^

TheGreatDuck

lol

MarksCode

5:04 AM

Did you guys know the first computer bug was an actual insect they found that flew into a transistor and burned it out?

TheGreatDuck

all OSes will do it

it's just the size of the code

the more features, the more risks

Faust7

its just too much effort to game in linux

TheGreatDuck

ironically game maker 8.0, which was made for windows only... runs better on linux

Faust7

lol

TheGreatDuck

i hear a few games that broke on windows 8 actually run great on linux

windows 10 fixed the issue

Faust7

5:05 AM

well the nice thing about windows is that its so broken

TheGreatDuck

something with midi files

Faust7

almost anything will "work"

its like a russian tank

TheGreatDuck

to be fair Game Maker is a piece of shit though

Faust7

no onw knows why it runs

but it doesnt really break down pernamently

TheGreatDuck

i mostly use it to take advantage of the game loop and graphics

so...

that's probably part of the issue.

anyway

it's late

Faust7

5:07 AM

enjoy some advanced napping

TheGreatDuck

goodnight. Also, why does chat stop you from messaging simply from posting a little fast?

nah. I'm gonna go lie down and watch youtube.

Daminark

Probably to avoid bots

TheGreatDuck

*boots

Faust7

Are you a robot duck?

TheGreatDuck

Worse. I'm a programmer, which means I type so fast that even posts like this seem like flooding with spam posts.

Faust7

5:09 AM

well im going back to figure out how calculus works for awhile enjoy your tube of U

Daminark

A duck versus a bot

3

FIGHT

TheGreatDuck

I also have a latent ability to write a 'small' writing assignment, specifically due to the fact that I type so fast and quickly write thousands of words. It's not unusual for me to write 500+ words a day and end up with a 8000-10000 word paper.

Faust7

couldnt the duck just fly away?

TheGreatDuck

dear god. I'm having flashbacks to 2013

Faust7

2013 wasnt so bad

TheGreatDuck

5:10 AM

wait for it...

the-cult-of-duck.wikia.com/wiki/…

literally duck VS bots.

shit

Faust7

wow thats alot of caps

TheGreatDuck

part 3

we used all caps for titles. It was our way of doing bold headings way back when.

ironically we've come full circle

the game I'm making is actually a really random prequel to all that. But don't tell anyone. It's kind of the obscure secret.

Faust7

^^

TheGreatDuck

i wouldn't say plot twist since it's set like 1000's of years in the past. XD

Faust7

im mor eof a rpg fan than builder fan

TheGreatDuck

5:14 AM

lol

it is a turn based rpg

grid based one, like the fire emblem games if I hear the rumors right

Eric

Quick question, for a matrix norm
\[
\frac{1}{\Vert A \Vert}
\]

TheGreatDuck

i've never played that

anyway, goodnight

Faust7

i really need to install latex on the computer

Daminark

sharelatex.com works as well

Faust7

most of the time i can just read it but i have no idea what eric just said

Eric

5:17 AM

Quick question, for a matrix norm
$$
\frac{1}{\Vert A \Vert} = \sup \frac{\Vert x \Vert}{ \Vert A x\Vert}
$$

is that true?

Faust7

im not understanding it correctly (ifi was id assume it would be exactly that no need for sup)

Icche Guri

Hello guyz

Faust7

morning

Icche Guri

good morning

I have one very easy problem

Faust7

dunno bout the good part but alright ^^

Icche Guri

5:22 AM

I have solved it

But the answer seems to wrong

Given two points in 2d space, I have to find the size of the largest square that can be drawn centered at those points such that, the squares do not intersect ( they may touch each other but must not intersect )

For this problem , I have found the distance between centers of two squares

Then the answer will be simply distance/2 .

Am I doing something wrong here ?

Faust7

each ahs an x,y cord

diffrence squared sq rted

Icche Guri

what is ahs ?

Faust7

has*

Icche Guri

so what will be the procedure to solve this problem ?

Faust7

$\sqrt {(x_0-x_1)^2 + (y_0 -y_1)^2}$

Icche Guri

5:25 AM

Yes I have applied this formula

Faust7

thats the distance bewtween the 2 points

ok

Icche Guri

Then the ans will be simply distance/2 .

Is it right ?

Faust7

take half the x distance and half the y distance thats the largest each square can be

Leaky Nun

@IccheGuri you don't need /2.

Icche Guri

So what will I need ?

Faust7

5:27 AM

oh

Icche Guri

@LeakyNun

Leaky Nun

Just the distance itself.

Faust7

shit

hes rite

Leaky Nun

@Faust7 language.

Icche Guri

why should the answer be just distance itself ?

@LeakyNun

Leaky Nun

5:29 AM

@IccheGuri draw a diagram.

Faust7

uh sorry ?

didnt think anyone would find that offencive.

Icche Guri

I have to draw two square between two points

Leaky Nun

@IccheGuri draw it and upload it.

Icche Guri

ok

Faust7

got it?

Icche Guri

5:38 AM

I am drawing a diagram to verify my argument

Here the distance betweeen tho centersof square is 4

got it

Faust7

whats the length of one of the sides of the square

Icche Guri

4

Leaky Nun

@IccheGuri nice

Icche Guri

What will be the side length of the largest axis parallel squares centered at points A and B ?

Leaky Nun

@IccheGuri max(|x1-x2|, |y1-y2|)

again, draw a diagram, and it will be apparent.

Icche Guri

5:46 AM

What is to be meant by this question ?

What will be the side length of the largest axis parallel squares centered at points A and B ?

Leaky Nun

"axis-parallel square"

is a square whose sides are parallel to the axes

the axes being the x-axis and the y-axis.

Faust7

the diagonal length should equal the distance no?

Leaky Nun

@Faust7 draw a diagram.

Faust7

nvm

Icche Guri

then why the answer is max(|x1-x2|, |y1-y2|) ?

Leaky Nun

5:50 AM

@IccheGuri have you drawn a diagram?

Icche Guri

Leaky Nun

@IccheGuri what is AB is not horizontal?

Faust7

move the centre point of the red square up one point

Icche Guri

ok I am drawing a picture in where AB is not horizontal .

Faust7

then try moving it up 5 points

Icche Guri

5:52 AM

what is the mathematical logic of this answer max(|x1-x2|, |y1-y2|) ?

Leaky Nun

@IccheGuri draw it first.

MarksCode

Can anyone confirm this for me please:

$(1 + \rho + \frac{\rho^2}{2!} + \frac{\rho^3}{3!} + ... + \frac{\rho^n}{n!} + ...) = e^\rho$

Leaky Nun

@MarksCode that is correct.

MarksCode

is this some sort of summation?

Leaky Nun

@MarksCode yes.

$\displaystyle \sum_{n=0}^\infty \dfrac{\rho^n}{n!} = e^\rho$

Faust7

5:53 AM

@IccheGuri draw the two pictures with the red square shifted up one point then 5 points

MarksCode

Thanks @LeakyNun

Leaky Nun

@MarksCode no problem.

Faust7

what happened the size of the square when you shifted up one point? then what happened when u shift it up 5 points?

Icche Guri

Leaky Nun

@IccheGuri draw AB neither parallel to the axes nor diagonal.

Faust7

5:57 AM

sorry you said the distance was 4 points so i have confused you

Icche Guri

ok

Leaky Nun

that's better

can you see it now?

wait

@IccheGuri I thought the two squares have to be the same

Faust7

those 2 squares arent the same size...

Icche Guri

I have to find the side length of the largest axis parallel squares centered at A and B .

ok

According to the problem format the squares have to be equal . So I have done mistake in drawing the diagram

Faust7

Anyone know what one would need to understand to get through an explanation of C* Algerbra?

Icche Guri

6:06 AM

now explain the issue

Faust7

the centres got futher away then when they were in line with each other yes?

did the squares get any bigger?

Icche Guri

I have not understood your words

Faust7

sorry

these squares are the same size as they are in the diagram you drew

but the centre of these 2 squares is closer together

Icche Guri

ok

then ?

Faust7

if you keep moving the second square up eventually when it passes the point where the x and y distance are the same

the squares will get bigger

thats why i was trying to get you to draw one with it up slightly and then up alot whichever diffrence whether it be in the x or the y is largest determines the size of the squares

if you used rectangles this wouldn't be the case of course... it would be an average...

Sorry iam clearly not qualified to explain this :(

Icche Guri

6:14 AM

ok I have understood

Faust7

i guess you could say the logic is coming from the fact that you MUST have a square not a rectangle

so even though one side could be larger it doesnt help you...

what class is this for if you dont mind me asking?

Icche Guri

I am solving a programming problem

This problem is in in basic geometry category

MarksCode

I can't wait til summer already, going to be interning at a cool company :)

Just gotta get this dang take-home final over with :(

Faust7

ah i know very little about programming

and appertnly very little about geometry lol

Icche Guri

in where are you studying ?

Faust7

6:21 AM

Math

never done basic geometry though

honestly i have no idea what im doing but im allegedly good at whatever it is im doing

Icche Guri

What will be the formula if two square is not of equal size ?

Faust7

make one square a point

the other one as large as possible

MarksCode

Anybody want to cry with me as I try doing this take-home final?

Icche Guri

What will be formula for the above figure ?

Faust7

could you restate precisely what your asking for?

MarksCode

6:31 AM

(╯°□°）╯︵ ┻━┻

Faust7

lol

MarksCode

//^ ^\\
(/(_*_)\)
_/ \_
( ) ( )

oh god

Faust7

i dont think thats an answer for your take home final

MarksCode

that dog got messed up

Icche Guri

I have to find the side length of the largest axis parallel squares centered at A and B

MarksCode

6:32 AM

//^ ^\\
(/(_*_)\)
_/'''\_
(,,,)(,,,)

I give up

sorry for wasting you guyss time

Icche Guri

@Faust7

MarksCode

.......//^ ^\\
......(/(_*_)\)
........_/'''\_
.......(,,,)(,,,)

Ok seriously Im done now

Faust7

if both squares have to the same size that make sense

if they dont have to be you could just keep making the pink square smaller and the red one bigger until the pink one is simply a point

anyway the same formula will wokr that Leaky gave you for the second picutre

the length f the side of each of the squares will need to sum to two times the largest diffrence

(when you make them the same size your splitting that 2d between each square giving you a distance of d for each one

Icche Guri

6:51 AM

I have not understood this line

the length f the side of each of the squares will need to sum to two times the largest diffrence

@Faust7

MarksCode

7:22 AM

hi all

Does this look right? $\sum_{k=0}^\infty k\frac{\rho^ke^{-\rho}}{k!} = \rho$

Astyx

Yes

MarksCode

Ok thanks

I just found the answer online, I have no clue what it actually means

SteamyRoot

wait, no

wait, yes*

Astyx

You can cause the first term is 0

SteamyRoot

Yeah, indeed.

And then of course the sum is just the power series expansion of $e^\rho$

MarksCode

7:34 AM

Its a problem about queuing systems

Any of you familiar with those?

SteamyRoot

Nope :/

MarksCode

awwww mannnn

Icche Guri

Given two points in 2d space, I have to find the size of the largest square that can be drawn centered at those points such that, the squares do not intersect ( they may touch each other but must not intersect )

I have to find the side length of the largest axis parallel squares centered at A and B

Icche Guri

9:49 AM

Anyone here ?

SBM

Hello

Icche Guri

Hi

Leaky Nun

@IccheGuri does this solve your problem?

Tim The Enchanter

10:06 AM

Well I'm back to MSE. It's been a while.

Icche Guri

what will be the output for this input ?

3 6 7 12

Tim The Enchanter

@IccheGuri Dude what? Are those meant to be the points (3,6) and (7,12)?

Icche Guri

Yes

Tim The Enchanter

Nvm misunderstood the question. It ought to be 6

Icche Guri

Have you read my problem ?

What is the reason for 6 ?

Yes the ans is 6 but how ?

@TimTheEnchanter

Tim The Enchanter

10:20 AM

I'm typing, please wait

Icche Guri

ok

Tim The Enchanter

The vertical separation is greater than the horizontal, so the squares of greatest size will have a common edge parallel to the x-axis ( y = 9 ). From the diagram it should then be clear that the side is $y_2 - y_1 = 6$.

Icche Guri

So the ans is Max(abs(x1-x2),abs(y1-y2)).

Is it ?

Tim The Enchanter

Yes

Balarka Sen

10:48 AM

@PVAL-inactive mathoverflow.net/questions/54143/…

Maybe you have seen that before though

Simply Beautiful Art

12:02 PM

@Secret Here's an ordinal collapsing function for you:

$$C(\alpha)_0=\{0,1,\omega_1\}\\C(\alpha)_{n+1} =C(\alpha)_n\cup\{\gamma+\delta,\gamma \delta,\gamma^\delta,\chi(\gamma),\psi_\gamma( \eta)|\gamma,\delta,\eta\in C(\alpha)_n \land\eta<\alpha\}\\\psi_\beta(\alpha) =\sup\{\max\{\gamma_n| \gamma_n\in C(\alpha)_n\land \gamma_n<\chi(\beta)\} |n\in\mathbb N\}$$

$$D(\alpha)_0=\{0,1,\omega_1\}\\ D(\alpha)_{n+1}=D(\alpha)_n \cup\{\gamma+\delta,\gamma\delta, \gamma^\delta,\omega_{1+\gamma}^{CK}, \psi_\eta(\gamma),\chi(\eta)|\gamma,\delta,\eta\in D(\alpha)_n\land\eta<\alpha\} \\\chi(\alpha)=\sup\{\max\{\gamma_n| \gamma_n\in D(\alpha)_n\land \gamma_n<\omega_1\}|n\in\mathbb N\}$$

Secret

12:31 PM

@SimplyBeautifulArt OMG we are going beyond Church Kleene now? I thought that barrier was insurmountable since everything after that is incomputable (except for those uncoutable ordinals that corresponds to cardinals, which we still have a recursive map for them

Simply Beautiful Art

@Secret Wdym?

The ordinal collapsing functions are designed to take uncomputable ordinals and map them to computable ordinals

Secret

$\omega^{CK}_{1} < \omega^{CK}_{2}$?

Ah I see, I did not realise it can also handle uncomputable ordinals, I thought it only handle the recursive ones

Simply Beautiful Art

The notation itself must be recursive, but it should be able to handle any ordinal

Secret

Looks like there are going to be more interesting fixed points to see from uncomputable ordinals. Cannot wait to get back to it after I finish this dreaded writeup

Writing is always painful

Simply Beautiful Art

Any ordinal that doesn't directly influence the notation gets collapsed into the greatest ordinal below it that is within the notation

Transcript for

$Mathematics$ Mathematics