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01:00 - 20:0020:00 - 00:00

8:00 PM
@Ramanewbie i saw that it is a text not an image, it means cheating is available
 
@Ramanewbie are you serious?
 
softwares cant just parse text in images
 
@lucas Just joking -_-
 
I can't get adult jokes... xD
 
Huy
@LucasHenrique: it means to play something unprepared. like if you're with a friend and he repeats a couple of funky chords on his guitar, you can just jump right in and play something awesome with him
 
8:01 PM
@lucas ;)
 
*pun intensifies*
 
@Agawa001 But how do you get that text in real time ?
 
@robjohn I have some fun investigating some unusual variable changes coming from my research. The thing I wanna say is that using the proper variable change can make the difference between the worst possible form of the hell and paradise for some integrals.
 
@Huy Oh, that kind of improvise. I know even what the word means if we talk about music but I didn't associate. Yes, I can :D
 
@Ramanewbie theres specific jscripts for that
 
8:02 PM
I'm not like a professional but I have some melody inside me
 
Huy
ok
at least something
practice it more! :D
 
@agawa Alright, idk js very well
 
@Huy but I can (`o_o´)
 
Huy
practice makes better
 
What did you play on the piano
 
Huy
8:04 PM
amelie
:D
was my first piece
I was in oxford and they had a piano and I was bored so I decided to learn amelie
after that I had some lessons and just wanted to learn basics, how to position fingers and move them properly etc so I could keep going by myself
 
@Ramanewbie here is
var $sourcewords =
'the name of very to through and just form in much is great it think you say ' +
'that help he low was line for before on turn are cause with same as mean ' +
'differ his move they right be boy at old one too have does this tell from ' +
'sentence or set had three by want hot air but well some also what play there ' +
'small we end can put out home other read were hand all port your large when ' +
'spell up add use even word land how here said must an big each high she such ' +
^ you can find the text here
 
@Huy the complete one? Both are pretty easy lol
 
Huy
well yea
 
@Agawa001 no...
Of course it's very easy to make such a script when you know the text in advance, but it changes every time you reload the page !
 
Huy
what do you expect as a first piece
can't start with chopin
 
8:07 PM
(the problem is that the pro say that mozart is easy, so...)
@Huy ^
 
Mary had a little lamb.
 
Huy
ok?
 
@Huy you were in oxford?
 
Huy
at some point in my life, yes
 
studying?
 
Huy
8:08 PM
@LucasHenrique: youtube.com/watch?v=x3omzs0lBKk for example this improvisation. the part at 3:24 is just wonderful imo
 
Huy
@skillpatrol yeah, but not at oxford university
 
I see.
 
GODDAMMIT.
 
@huy You did that ?
 
Huy
8:08 PM
@skillpatrol: just at a school to improve my English, but I had a looot of free time
@Ramanewbie: no that's not me
 
@huy oh alrigh
 
@Huy I can but he's a pro so not like him
 
Huy
idk if he's a pro
but he's definitely better than I am ^^
 
he got 400,000 subscribers
need another clue
 
Huy
yea
if you watch gaming channels, there's plenty with more subscribers of people who are not pros
 
Huy
if you enjoy covers, you should check him out though
 
The entire channel
 
Huy
he has some really outstanding ones
 
@Ramanewbie it is just a stupid js and i could deobfuscate it its just i dont have time for it
i reversed systems which looked harder to decrypt
 
@Agawa001 I mean, Does learning math => (number, theory, geometry, statistics, calculus, linear algebra etc) help you with programming problems, especially the puzzling kind, like google code jam ?
 
8:13 PM
@gideon im not into google jam, but it helps indeed
about projecteuler and spoj.com, it helps way far
 
@gideon like hell it wouldn't. of course
 
@Agawa001 I don't see what you mean. Where did you get that ? This script just creates a variable containing a text and doesn't event send it to the textbar.
@Agawa001 And how is it obfuscated ?
 
Is there someone else who is into projecteuler?
 
Huy
@gideon: in my experience, it doesn't. I did decently well on most math things but algorithms I am really terrible at
but if I'd study algorithms specifically, I'm sure I'd improve
 
@gideon if you look at games' source code there's almost 50% math, 40% gui and 10% other
@Huy so you're good at math and you suck at programming :p
 
Huy
8:15 PM
programming and algorithms are really two things$
 
what would be programming without algs?
 
Huy
I can do a lot of programming without knowing anything about algorithms
 
that's simply beautiful
 
Huy
all the sorting algorithms etc I never knew before I studied them
so I basically did programming without knowing anything about algorithms for 5 years
 
oh that
I don't know algorithms but I don't suck at it
 
Huy
8:17 PM
or given some problem with runtime O(n^2) and I have to improve it such that it has O(n log n)
that kind of stuff
I suck at
 
@Ramanewbie look i dont have my tool-bag right now (firebug+tamperdata+greasemonkey) but if i give it much time, i can reverse this text-generating alg
it is just about time
 
Huy
@LucasHenrique: I can just imagine that as a background of some anime :D
 
@Agawa001 Ok.
 
do you guys like anime?
 
Huy
I should go to bed
good night all
 
8:20 PM
as you can see, my profile tells you I'm not a weeabo
@huy bye!
 
Later pal
 
lol programming without algorithms? how on earth should i guess what is it like , like programming arithmetic calculations or what
 
@huy See ya
 
@Chris'ssistheartist Yes, some of the nastiest integrals can be computed easily with the proper substitution.
 
@Huy Maybe we're alike, I've been programming for years and get paid a nice sum for doing a data collection application. No math involved.
However, there are a number of challenging interviews I'd like to get by better where they ask a lot of algorithmic problems.
Sometimes it's based on advanced high school math, but sometimes just based on a well known algorithm.
 
8:32 PM
maths pushed me to learn programming, i cant imagine another wayelse to go
 
I see. @Agawa001 I wish that were the case for me. It's the other way around for me. Programming is pushing me into math.
 
@gideon thats useless
 
what do you mean?
To be specific, I got this book :
 
I'm useless
 
maths come from itself
 
8:34 PM
I got this book : http://www.amazon.com/Algorithm-Design-Manual-Steven-Skiena/dp/1849967202

and I'm having a hard time following all the math that comes along with it! :(
 
not from programming or anything else
 
@Agawa001 thats exactly what i thought
 
@Agawa001 and physics
 
@Agawa001 @Lucas I don't mean math came from programming, I certainly understand how math is the underpinning of everything...
 
maths is the motherground of all these
 
8:36 PM
Hi @skillpatrol
 
@Agawa001 Over the years I've gotten bored of programming business programs.
 
Hi @morphic
 
@gideon do you program databases ?
 
@Agawa001 I need to work on my SQL but yes I have some DB experience. MS SQL.
 
yes databases dont require maths at all
 
8:40 PM
No no, I don't want to avoid math in any way. I want the better jobs out there. Some very high paying, but I don't get through the interview when it comes to the puzzle problems like on project Euler or code jam.
 
sql and apache need an enormous capacity to deal with databases
 
And when I read the algorithm books like the one I mentioned earlier, it's got tons of discrete math that I don't know yet.
So is my assumption correct that if I study math (discrete and calculus) I should understand these algorithm books better and therefore have a better grasp and program harder problems better.
 
@gideon thats wierd, in this country maths arent needed as a programmer, these programming-quiz arent among the job-interview
they just want you to deal with big mass of datas promptly
 
Begin by studying specifically for those puzzle problems at puzzles.se @gideon
 
Hmm. I've had interviews from Japan, Netherlands, Germany and they've asked a lot of algorithmic problems that require fast thinking.
 
8:44 PM
noone hire you here for scores you make in project-euler, or puzzles you solve
 
@skillpatrol @skillpatrol puzzles.stackexchange.com ??
Ah! Thanks
 
Knowing general algorithms is nice and all, but it's familiarity with your tools that will really makes you stand out.
 
@Boni yep, Yes, I could perhaps look at quick sort and be able to write in my primary coding language. But it's mostly when I get to the algorithm books like Knuth or Skiena that it's plain gibberish to me.
@Boni so I've started studying math on khanacademy.org and it's been slow :(
But I'm hoping it's not a waste of time.
 
8:49 PM
Knuth has written a book called concrete math @gideon
 
Because I have many programmers who say that math is not a requirement, but in my case, I do want to understand the math under the programming.
 
@skillpatrol ah. Thanks. Yep. I've heard of this one.
There's a hard cover version that costs like $100 ! wow. But given that I've tried so many options I might actually buy it.
Or perhaps a kindle version.
 
concrete? is it like discrete ?
 
@gideon from there you can go to his "art of programming"
@Agawa001 yes
 
8:57 PM
@skillpatrol that one I've looked at and it looks scary.
It is on my endless reading list.
 
You need the concrete math first @gideon
After all he is a mathematics Ph.D.
 
True. Yep. I've got a kindle version :D
 
That books is probably worth more of your time than any Khana Academy courses.
 
^
Just use Khan if you can't understand some topic in the concrete math book
 
i came a accross a free e-book entitled like this and havent downloaded it :S didnt know it is that important
 
9:04 PM
@skillpatrol that makes sense. Under the chapter sums I see a "Finite and In􏰌finite Calculus" sub heading, I don't know all too much calculus but I do know what a limit, derivative and Integral is.
Just haven't practised enough of the stuff to solve problems quickly.
 
Most importantly, have fun learning :-)
 
@gideon That's not what I meant. You should not need to implement those. You want proficiency and knowledge about what is already available for your language. You want to know the ins and outs, the quirks and bugs of existing implementations.
 
@Boni can be be more detailed, implement what exactly?
Anyway, I got concrete math on my iPad now. Lets see how that goes. Couldn't get shut-eye for hours over this and now it's 3am! I'm off to bed. Thanks @Boni @skillpatrol and everyone else who got involved in my hairy conversation I appreciate it :D
 
@gideon i love this site
 
9:22 PM
me too
 
I have a little question²
Given $f(x)$ and $g(x)$, find the area between $a$ and $b$ when $g(x)$ cuts $f(x)$
 
Any ideas?
 
that's what I mean
 
@skillpatrol I need ideas
 
@morphic about what?
 
9:33 PM
@skillpatrol math
 
Hello does anyone know how to generate random numbers such that their sum is zero?
 
x = rand, y = -x
 
@zed111 generate n-1 random numbers and pick the last such that the sum is 0
 
@AlecTeal Yes thats what I am doing now
 
9:34 PM
@LucasHenrique he didn't say how many. And the only sequence that ALWAYS sums to 0 is the sum of 0s
 
But is this a good method?
 
btw that image is about analytic geometry
I'm trying to proof projectile motion on inclined planes
 
@LucasHenrique do you know how to find the area under a curve?
 
integral
yes, then
 
Yes, a definite integral
 
9:36 PM
Oh, got it
so I have:
 
integrate both functions then subtract one from the other
 
what I want = $\int_a^b f(x) dx - \int_a^b g(x) dx$
yes
and $a$, $b$ can be found when $f(x) = g(x)$
 
Correct.
 
These chars are all utf8?
like integral or sigma
Another question: can't we represent $\stackrel{\to }{r}$ as a scalar function?
(physics)
 
What do you think?
 
9:46 PM
I think we can
 
How?
 
Well, $\stackrel{\to }{r}$ is nothing but two functions combined (2 dimensional vector)
If I could only see how
 
what do you mean by "represent as a scalar function"?
 
$f(x) = ax^2 + bx + c$
It's a parabola
(I'm talking about projectile motion!)
 
so, you're wondering when the range of (x(t),y(t)) is the graph of some function y=f(x)?
if so, vertical line test
 
9:51 PM
@anon yes
let me google that
oh, it can
at least on domain $[t, t_f]$
 
10:06 PM
Does anyone else get random downvotes from time to time?
For example, a 4 month old question of mine was at +5 for all that time and suddenly someone downvoted it without reason
It's not that I care about internet points, I just wonder if that's common
 
Yes, it is common.
 
@Krijn oh please, it would be worse for some
dont really care about 1 dvt, but a stream of downvotes ????!!!!
people were like crusading me or something, i dont really care lol
 
Yeah, I had something really weird with that recently
I improved my answer (was at +3) with some beautiful alternative proof and got 6 downvotes!
Which makes me wonder if I did something wrong, but nobody commented to tell me if I did
 
yes wish they do
just move on bud, just go on
 
Yeah I know, it's just... How do you say that in English?
The word that has the same feeling as uncomfortable
 
10:17 PM
@Krijn time will change, users will change, they will find your work interesting
@Krijn its wierd, i had almost similar thesis abut collecting dots by minimum number of lines
 
It's a nice solution though
What was your thesis?
 
not exactly focused on this but i v dealt with it using graph theory
its about data compression
 
$\stackrel{\to }{r}=\left[\begin{array}{c}x\\ y\end{array}\right],x=‖{\stackrel{\to }{v}}_{x}‖\cdot t,y=‖\stackrel{\to }{{v}_{y}}‖\cdot t$
Nothing so impressive about it
 
passing by too many rounds until finding optimal number of lines (not brute force)
 
How do I get this to a scalar function?
$\stackrel{\to }{r}\left(t\right)=f\left(t\right)$
 
10:28 PM
that equation makes no sense @Lucas
 
first one?
I just noticed $\stackrel{\to }{r}\left(t\right)$ is incorrect notation
anyways, I want to find a non vector-valued function from a vector-valued function
 
I assume $v$ is a vector?
 
Well, the image of that function is a $1$-dimensional line in a $2$-dimensional plane.
 
$\vec v$ is the initial velocity
 
10:34 PM
@LucasHenrique are you asking how to find f when the range of (x(t),y(t)) is the graph of y=f(x)?
 
use your words
 
lol
sorry
 
the range of (x(t),y(t)) is the graph of a function iff x(t) is a one-to-one function, in which case we can write y(t)=f(x(t)) then replace t with x^-1(t) and you get f(t)=y(x^-1(t)). that's how you get f() from x() and y().
 
wow
okay
Let me try to (firstly) read that
@anon why $y(t) = f(x(t))$?
 
10:43 PM
you know y=f(x) for some f, you want to solve f from that equation
 
oh, got it
@anon then with f(x(t)) = y(t) you solve for t right?
 
you replace t with x^-1(t)
to end up with f(t)=y(x^-1(t))
 
why x(x^-1(t)) = t?
 
you're asking why that's true?
 
Maybe the formatting is being troublesome. I don't know if x^-1 is (1/x) * t
 
10:55 PM
x^-1(t) is the inverse functions, not 1/x(t)
 
hmm
let me google that²
 
11:06 PM
Sometimes, mathematics is just weird
"more than 99% of groups of order less than 2000 are of order 1024"
 
lol
$99g/100$ that $g_o < 2000$ are of $g_0 = 1024$
I love math notation
 
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