The Whiteboard

Vivian

05:03

@Dvnamic

@World thank you so much

That is what I am looking for so much.

Kim Jong Woo

07:44

hello

thorsten müller

Hi

Kim Jong Woo

hey!

how are you

thorsten müller

found it :)

fine, thanks, how are you?

Kim Jong Woo

I am great

I began combing through academic papers on web data extraction

it's still an unsolved problem

there are many approaches and solutions

each with advantages and disadvantages

so I began reading these papers whenever I could find time

and I hate that I have to pay like $20 CAD for a freaking 20 page pdf

almost a dollar a page

I use google to find most papers but some pdfs are just inaccessible without a credit card

thorsten müller

Yes, and as soon as you find the interesting papers they hit you with math formulas and the big-O stuff is the most simple of it

You can find a lot of this stuff "online" for something like "free"

Do you have a usenet account?

Kim Jong Woo

07:47

ah?

what's usenet?

it's like a newsgroup from the 90s?

I think I've seen it before didn't know people still used it !

thorsten müller

Yes, it was there before the internet and still is

Kim Jong Woo

before the internet?

thorsten müller

We use it a lot, and there is far more than use groups

Kim Jong Woo

so how do I get access to it

thorsten müller

Yes, the concept of newsgroups worked without the heavy infrastructure necessary for internet

Kim Jong Woo

07:49

how does it work really

thorsten müller

You need a usenet provider

Kim Jong Woo

I hope I am not taking up your time

I see

thorsten müller

The basic idea is that you put something on your providers server

And then he puts it on the server of other providers

There other people can take it

So it's more decentralized than the internet and a touch slower

Kim Jong Woo

ah

so it's like tor

thorsten müller

With many providers you can get test accounts for free

Yes and no. I don't know tor enough, but tor is somewhere between newsgoups and internet

The other option are torrents, I once got 1Gig pdf files of CS books (about 10k). Rather unsorted, but all the "big" names in it. Though more risky depending on where you live.

Kim Jong Woo

07:52

holy

im totally fine with torrents lol

thorsten müller

But just to mention that there are sources. You really don't need that at all, since there is so much free stuff anyway

Kim Jong Woo

how do find free usenet providers

is it really worth paying for usenet?

also if you are worried about torrents

you can use vpn

I don't know tho...sometimes they might still be keeping log

thorsten müller

for me it is, I pay about euro 7.50/month

yes, but vpn is a lot of setup

Kim Jong Woo

what's it called?

thorsten müller

usenet is better for music

Kim Jong Woo

07:55

OpenVPN, download config file, bam good to go

thorsten müller

ewekea, they're in the netherlands

Kim Jong Woo

for music?

thorsten müller

flac & mp3 like you get with torrents

Kim Jong Woo

but are they actually really doing what they claim? remember lulzsec got busted for using vpn

I'd be even more nervous about downloading mp3 from usenet

imagine all the copyright trolls

thorsten müller

Nope, here in Germany that's ok. I can download "legaly" whatever somebody "offers". I'm just not allowed to upload or seed.

So usenet is safe for me. And the other advantage is that you get stable bandwidth from your provider. For that reason you find better quality (flac) instead of mp3 more often.

Have a look here: nzbsearch.net

That allows you to search what you could find in the usenet.

Kim Jong Woo

07:58

wow

what the

full album rips

thorsten müller

:)

Kim Jong Woo

is there an anonymous usenet service

or does usenet offer some encryption

I can't believe that this is still going on

never have I knew such an old technology could provide so much more

thorsten müller

Sorry, don't know. There are so many of them and you can access them through a VPN if you want. Some accept bitcoin or prepaid credit cards

Kim Jong Woo

do you know which ones accept bitcoin? wouldn't mind spending a few as I just invest in it

thorsten müller

Somehow nobody seems to care about it, because there are not that many users.

Kim Jong Woo

08:00

how come everyone doesn't use this?

why did they go after megaupload but not usenet?

napster but not usenet?

thorsten müller

No, sorry not right away.

Because those are big and loud

Too much noise. Especially Kim Dotcom the idiot can't shut up his big mout :D

Kim Jong Woo

HAHAHA

thorsten müller

Kids use it, kids don't use usenet. And kids are those who pay a lot for music.

It's just politics.

Do you know reddit?

Kim Jong Woo

yeah

I love reddit

thorsten müller

well, there are usenet subreddits (and tor, and torrent...)

there you can find out more about providers that may accept various payments

Kim Jong Woo

08:03

I wish reddit looked like ycombinator

thorsten müller

yes, design sucks a bit for reddit

ok, eweka.nl and cheapnews.nl offer both 10Gig free trial. Just have a look and you will see. And some of the newsgroups are quite active too, so that's another place to go and talk

Kim Jong Woo

08:16

NICE

thanks so much

so you just search for the title of the ACM paper

thorsten müller

yes, I didn't use it for that kind of paper yet, so don't know how much you can actually find.

but I think chances are better, since it's used less by kids

But as I said, there is a lot of free material if you want to learn.

Kim Jong Woo

yeah I would really like the ability to understand the math algorithms and notations

you said " they hit you with math formulas and the big-O stuff is the most simple of it" what did you mean by this

big o notation I understand

thorsten müller

Well, start to learn about that stuff somewhere. I actually started with Khan academy.

Kim Jong Woo

but really some of the stuff gets super complicated, and I just giveup, can't continue reading the paper because I lack the ability to understand

HOLY RAP

thorsten müller

Yes, you start to read over the formulas as long as you still get the text, but from some point things get "empty"

You understand less and less and then have to stop

Kim Jong Woo

08:25

yes

OMG it's free to

too

thanks so much

thorsten müller

I became far more fluent in the notation when I forced myself to learn latex

Kim Jong Woo

this single url will have profound impact on my life

latex?

thorsten müller

Hey, that's just where we start, Khan is for kids

Kim Jong Woo

the notation software?

thorsten müller

yes.

I started a Coursera course (another free resource). Never finished

But for the first week for example I wrote this wiki:

share.coursera.org/wiki/index.php/Crypto:Main

Well, for free courses: Coursera.org as mentioned, but many big universities offer free courses on everything CS related (and others). MIT OpenCourseware

Kim Jong Woo

08:29

I see

thorsten müller

ocw.mit.edu maybe the most well known. Harvard and whatnot have similar sites

Kim Jong Woo

you've given me a mind blowing amount of new information

thorsten müller

You're welcome :)

Kim Jong Woo

the amount of stuff that I can now find is staggering

coursera why did you never finish?

thorsten müller

Got a new job and didn't have the time then.

When you start somewhere new they always have a big heap of problems

Kim Jong Woo

08:31

hahaha nice

thorsten müller

So I had to work long hours and sort that out

Kim Jong Woo

what is your current position?

thorsten müller

But will go back to this sooner or later.

Kim Jong Woo

I am an intermediate developer at a small startup

well more of an ISV

yeah

job does get in the way

thorsten müller

I'm the web developer for a medium sized retailer for hifi and mobile products

Kim Jong Woo

08:32

it's 1:31 AM here and I am trying to catch up

nice

thorsten müller

yes, time is always the big issue.

My main goal is to learn Haskell right now

Kim Jong Woo

I sleep less

that was the only possible solution

Haskell?

hey I actually gotta run

thorsten müller

Be careful with that, can strike back with lack of concentration

Kim Jong Woo

sorry to cut this conversation short but I really enjoyed talking with you

thorsten müller

Better to be fit for 4 hours than sleepy for 8

Kim Jong Woo

08:33

I find that after I started to run

I started sleeping less

thorsten müller

no prob, have to get som,e work dome too

Kim Jong Woo

I started eating less

cool ttyl

thorsten müller

that's a good thing and do some sports

Kim Jong Woo

wish stackexchange had Private messaging function

thorsten müller

but I'm 42 and in my 20s things where easier :)

Kim Jong Woo

08:34

hahaha

thorsten müller

are you on G+ ?

Kim Jong Woo

what is that

oh google plus

I think so but I rarely use it

do you have twitter I can follow

thorsten müller

no, no twitter

I don't use G+ much too

Kim Jong Woo

do you have skype?

thorsten müller

no, I'm quite lazy about all those social thingies

Kim Jong Woo

08:37

same I rarely use these things

it's too much hassle

thorsten müller

Anyway, I'm here nearly every day

Kim Jong Woo

haha cool I will drop by sometime

thorsten müller

So are others. It's a slow time right now (10:30 here in Europe) in a few hours Yanniz and others will drop in

Kim Jong Woo

alright I must sleep after all...I am human

Stack Exchange

12:13

Blog - Stack Exchange: Podcast #49 – The One Where We Edited Out The Title Reference

Alex Miller on June 11, 2013

Welcome to episode 49 of the Stack Exchange Podcast! We are welcoming special guest Matt Grum, as well as usual suspects Joel, David, and Jay. Matt is the top rep user on Photography. He’s got 957 answers (and has never asked a question)! He’s a photographer and a developer, so his exposure to the Photography site came from his involvement with Stack Overflow

First, some site milestones! Blender is in public beta. (Matt is way more qualified to tell you what Blender is than any of the rest of us.) Also, the second attempt at a Freelancing site is successfully moving to public beta. …

Retief Fourie

13:45

Hi everyone.

thorsten müller

Hi @RetiefFourie

Retief Fourie

Anyone doing iOS development.

Retief Fourie

14:04

I only started iOS development last week and I was wondering if anyone saw the iOS 7 release conference. Wanted to hear some opinions

thorsten müller

@RetiefFourie you may have more luck in one of the iOS chat rooms over there at StackOverflow (not that much activity here right now anyway)

Retief Fourie

Ah thanks. Pretty new to the site. I'll pop over to one of the others. Hope you guys have an awesome day!

thorsten müller

Thanks, hope you find what you look for

Jimmy Hoffa

14:34

@thorstenmüller Trying to learn some Haskell eh? Have you started or just thinking about it? heh

thorsten müller

actually started. quite proud that yesterday I was able to follow this cute example in Real World Haskell where they describe how to implement foll with foldr

*foldl with foldr

Jimmy Hoffa

awesome

Pretty soon you'll start thinking in terms of folds a lot, which kind of sucks because it's a structure for solving problems which very few people are familiar with

thorsten müller

To some extend I'm prepared to some usage like map from Ruby

Jimmy Hoffa

@thorstenmüller Now, implement map with fold :D

thorsten müller

@JimmyHoffa ah that was the example before that one, that was easy (or easier than the foldl)

Jimmy Hoffa

14:41

aye

thorsten müller

foldl had that mean trick with the id function and creating a series of functions

what really is a pain to me is that you can't throw out some debug messages as in Ruby or other languages

Jimmy Hoffa

How do you figure?

thorsten müller

the foldl example?

Jimmy Hoffa

You can, and it's quite easy, but you probably won't know how until you get a bit further because debug messages are an IO action

do you work in ghci?

thorsten müller

Yes

Jimmy Hoffa

14:44

(also, do you use emacs? it's the bees knees for haskell, I never learned emacs until learning haskell)

leksah is good too if you're used to a large IDE (I've been in visual studio for over a decade so I started with leksah before migrating to emacs)

thorsten müller

I played around with some other tutorials that were more on the output side. But just don't know yet how to put that just into any other code

I mostly use sublime

Jimmy Hoffa

does sublime have haskell plugin stuff to run the script for you?

thorsten müller

I used emacs once in a while but no that big fan (yet)

don't know, didn't look for a plugin. I work on linux and having open the terminal and editor on different workspces

so I really don't need to have everything in a single program

at least it has syntax highlighting for haskell

Jimmy Hoffa

Aye

foldl1 f xs = foldr1 f $ reverse xs

hehe

but I'm sure that's not what it was asking for, you probably had to nest the elements in a stack of functions

thorsten müller

Oh, it was an example, not an exercise. I only had to understand the code that was given there.

Jimmy Hoffa

14:54

ah

Dagelf

Hi All... I just discovered the SE chats... Sooo coool. I've long been saying IRC needs a makeover. Two questions jump to mind:
1) Why isn't SE open source so I can add word clouds and custom filters & bots and use a self-hosted offline version for our office? ... Or is there a better solution?
2) Why am I too lazy to dig for a FAQ... oh it's because I'm human and it's easier to ask than to look... but only if you're lucky :-)
3) Oh yeah... another thing I'd add: Multiple lanes per room... ie. shared "private" topic-based conversations or multiple rooms in one room...

Jimmy Hoffa

debug messages would be like...

foldl1 f xs = foldM1 (\x -> f x >>= (\y -> print y >> y)) $ reverse xs

the only difference is that's no longer :: (a -> b -> c) -> a -> [b] -> c and now results in IO c

which is harmless once you get comfortable with monads

thorsten müller

this was the example:

Jimmy Hoffa

that's actually the wrong sig for my func but you get the idea

thorsten müller

myFoldl f z xs = foldr step id xs z where step x g a = g (f a x)

the main trick was to find how it handles partially applied functions

Jimmy Hoffa

15:00

aye

thorsten müller

Without parentheses it becomes a bit nasty to find this.

First thing I did was looking into the Prelude source to find what exactly! foldr would do with its input

Dagelf

:-) What are you guys talking about?

Jimmy Hoffa

Haskell

thorsten müller

@Dagelf my first steps into the slightly irritating world of haskell programming

Jimmy Hoffa

@thorstenmüller you use :t in ghci on stuff yeah?

thorsten müller

15:04

all the time

Jimmy Hoffa

hah slightly? Oh man, it's way more than slightly

illuminating as it is, learning it feels like getting a brick to the head

thorsten müller

yes, I'm don't have a great mathematical background

It's like a complicated puzzle

Jimmy Hoffa

yeah I have none as well

but the maths aren't all so necessary

It's all mathy stuff most people who study math never learn anyway

thorsten müller

So I decided to go into this really slow, read source code and don't hurry, read several tutorials in parallel

Jimmy Hoffa

so it wouldn't have helped if you did

learn you a haskell is the best in my eyes

it goes really slow from the ground up

RWH moves a lot faster direct to high level things

thorsten müller

15:06

no, you don't exactly need maths, but having worked with complex formulas should maybe help with that kind of thinking

Jimmy Hoffa

maybe..

thorsten müller

I worked with Learn you a Haskell to (and will again)

Jimmy Hoffa

Either way, the rule of thumb LYAH gave is a great reminder to always remember to get you in the mindset for folds: Anytime you have multiple things and you only want one, you want a fold

thorsten müller

but at some point I got lost in it, because some stuff wasn't explained very thorough

Jimmy Hoffa

Yeah, I had the same issues, it goes slow and is very thorough but it works well if you keep going back to it

thorsten müller

15:09

I think on the usage level for things like folds I can handle this quite well as long as it's just working through a list

Jimmy Hoffa

it quickly becomes working through other things

thorsten müller

I use this in ruby quite often.

Jimmy Hoffa

but that's later on

have you gotten your head around the type system at all yet?

That's the real bread and butter of haskell, and definitely the hardest part

thorsten müller

Just like the foldr to foldl thingy gets tricky if you don't return values but functions (that are only partially applied)

Jimmy Hoffa

think about this then, given [+1, *2, mod 4, pow 3] how would you make fold apply those functions one after another to a value?

thorsten müller

15:12

sorry, have to go right now. will be back in a few hours. but interisting problem, will think about it later

Jimmy Hoffa

so you end up with ((((x+1)*2) mod 4) pow 3)

yep, later

Dynamic

16:55

Can I get a mod to discuss a possible contest with me over in the contest chat room? chat.stackexchange.com/rooms/2654/programmers-se-contest

thorsten müller

17:20

@JimmyHoffa ok, I'm back and have somer coffee

lets see, I just tried in ghci and it's easy enough to put functions into a list.

where would I ind the pow function?

Jimmy Hoffa

18:07

@thorstenmüller maybe pow isn't a function, I was presuming that would be for to the power of (as in an exponent)

but if not, just use some other math function

thorsten müller

seems there is ** and ^ and ^^ for exponents

Jimmy Hoffa

Prelude> map (\x -> x 3) [(+)1, (-) 3, mod 4, (*)8]
[4,0,1,24]

thorsten müller

but that's applying them each individually. I thought you meant somethuing like foldl and getting

Jimmy Hoffa

take that list and make each function apply in sequence to a single value

thorsten müller

3 +1 -3 mod 4 * 8

Jimmy Hoffa

18:12

Yeah, just showing map as an example

thorsten müller

ok, map would have been easy

Jimmy Hoffa

Up to you to figure out how to do it with a fold

to sequence them

thorsten müller

i got this function in a list thing

but it's tricky to get things in the right place so it uses the function from the list

tried with a "where" defining a method that takes the params

but didn't get it right yet.

with foldl in any case the order of operastions seems to be wron way around

but just started

something like

foldl (\x f -> f x) 5 [(+)1, (-)3, (+)4, (*)2]

but result is wrong, got something mixed up

Jimmy Hoffa

is it? :)

thorsten müller

gives 2 should be 14

Jimmy Hoffa

18:27

...should it?

thorsten müller

if processed in simple order (ignoring that multiplication has higher prio)

psr

If +4 really means mod4 then it should give 2.

Jimmy Hoffa

not quite

@thorstenmüller you're thinking about this:

Prelude> foldl (\x f -> f x) 5 [(+)1, (flip (-))3, (+)4, (*)2]
14

thorsten müller

no, i took it as i wrote it here. replaced mod 4 because that way i can handle it easier until i find how it works

what's that flip thing doing?

Jimmy Hoffa

flip f x y = f y x

psr

18:30

It's doing 3-6, not 6-3

thorsten müller

i got it like this: 5+1 = 6 - 3 = 3 + 4 = 7 * 2 = 14

oh damn, yes sure

Jimmy Hoffa

that dang subtraction not being commutative always screws everything up heh

thorsten müller

i was looking where it went wrong exactly, because with simple rows of additions it worked

yes, that's why i first simplified a bit and removed the mod (ended up with 0 as result too often, mod is rather brutal)

only addition was too simple, because then the order doesn't matter at all

but the flip limits its usefullness

that way you would need to know what functions to expect in the list

psr

OK, so why does it do 3-6, instead of 6-3? If the explanation is anything other than "it's defined that way".

thorsten müller

is it? if i have a function (-) x y and that should calculate x-y then partially apply 3 for x, i get a function that returns 3 - y

that's what happens in (\x f -> f x) foldl gives it the (-)3 function and the value (say 10). it calls (-) 3 10 and returns the result. anything more complicated than that?

psr

18:45

No, it's just if you think of the list as a sequence of operations to be performed on the seed value, you naively expect "-" to subtract the number from the running total. It's just that - as commonly used doesn't take the running sum as the first argument, which would be nicer here, if such an operator were in common use.

thorsten müller

yes, i hadn't analyzed the problem that far. was looking in the wrong direction first, thought maybe the whole list is applyed the wrong way around. that for i started to reduce further. would have found that sooner or later. but good to know of this kind of trap.

psr

Good for me to remember that partial application starts by applying the first argument - not the one you thought in your head would be appropriate.

thorsten müller

can a program get this info at runtime?

so you could wrie something that would make sure to use flip where necessary?

psr

How would it know what you intended - if it's different than the normal functionality? You could easily define a flipped version of subtract, though.

thorsten müller

19:01

is there a way to partially apply on a specific function param?

like (-) _ 3 instead of (-) 3 _

funny, Prelude defines subtract for flip (-)

psr

Good question. Bear in mind I'm probably a bit behind you in Haskel knowledge.

thorsten müller

can't be much :) I'm not that far yet

for anything with two params you can use flip and go oin from there. would be easy enough to define something similar to flip for functions with more than two params

Jimmy Hoffa

19:51

@psr You can (+)-3 instead

but yeah, when dealing with infix functions you always have to be mindful of the actual parameter order is left to right

so (-)3 is 3- and /3 is 3/

@thorstenmüller so have you gotten to data types yet?

thorsten müller

20:07

yes, sure. that's quite early in most tutorials, since at least basic understanding is necessary for everything slightly more complex like pattern matching.

Jimmy Hoffa

20:30

@thorstenmüller Really? I found it all quite confusing to get my head around how to create useful data types with type classes and such

gnat

21:53

Don't know why this is getting so many upvotes; it doesn't explain anything. This isn't a fashion contest; use your votes wisely, people. — Robert Harvey 2 hours ago

3

Q: The association bonus should not enable users to vote on every site

The number of upvotes for a question is a flawed measure of question quality, one particular issue is that the amount of exposure a question gets matters a lot. Questions that were linked in the hot questions list tend to get an enormous amount of votes, much more than any questions gets organica...

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