12:05 AM
@AlexA. φl

@Dennis ?

Fail?

Oh haha

Option B is correct btw.

\o/
Note that I intended "fai" to rhyme with "eye."

12:10 AM
Fine. I have an accent.

Do you say it "fee"?
φ = fee or φ = fahy ?
I am confused.

support for option A: PhiNotPi rhymes

It doesn't have to rhyme.

this is correct but it's cool if it does

No, it's much cooler if it doesn't.

12:14 AM
???
this is nonsensical to me

40

I am worried that "nonsensual data" might come across as data that does not have a lot of erotic vibe....

i feel bad for laughing at this question written by someone who is learning the language i take for granted
but i'm still doing it

Well, maybe I should throw away my nonsensical data (since it does not make sense anyway) and go get some sensual data.. — BoZenKhaa Apr 22 at 12:15
Based on his other SE activity, he actually has really good English.
What's a decent tolerance for declaring some floating point value to be "equal" to an integer?

that's not an answer but it's kind of relevant and i like it

That person's first name is like my grandpa's first and last name smashed together.

12:26 AM
First name Russel?

No
Rustem

@AlexA. it would probably be proportional to the size of the number

What

well
what are you using the equality for?

Shits and giggles

12:28 AM
It should be less than one giggleth of a shit difference, then.

> shit difference
3

You could make it within two ulps or something

ulps?

In computer science and numerical analysis, unit in the last place or unit of least precision (ULP) is the spacing between floating-point numbers, i.e., the value the least significant digit represents if it is 1. It is used as a measure of accuracy in numeric calculations. == Definition == In radix b, if x has exponent E, then ULP(x) = machine epsilon · bE, but alternative definitions exist in the numerics and computing literature for ULP, exponent and machine epsilon, and they may give different equalities. Another definition, suggested by John Harrison, is slightly different: ULP(x) is...

I feel like there's all this fancy computer science terminology I don't understand, like "shit difference," "ulp," "giggleth"...
8

12:34 AM
I think APL considers numbers equal if the ratio is less than (1+2^-32)

@ThomasKwa That is an interesting factoid. Where did you find that information?

I just looked up some site about an APL implementation, and then I tested it
doesn't seem to be exactly right now, though

Which implementation was it? I know Dyalog and ngn give different results for floating point equality.

SHARP APL
Yeah, it's definitely not correct with Dyalog

I've never heard of SHARP APL!

12:40 AM
oh, here's what Dyalog uses:
I feel like I've read that article before, but I don't remember when.
it's (|x-y)≤⎕ct×(|x)⌈(|y) for some ⎕ct ≤ 2^-32

My default Dyalog desktop comparison tolerance is 1E¯14

Okay, so, there's a really old question on Huffman encoding, which asks for a Huffman tree. What I had in mind was that programs would compute the Huffman coding and then output each character along with its binary representation, sorted from shortest/most frequent to longest/least frequent. Are these different enough that they wouldn't be duplicates?

1:01 AM
It would not be a duplicate, because you can't trivially modify answers to that question to answer your new question.

Excellent.
I shall sandbox it now.

1 hour later…
Anonymous
2:13 AM
@AlexA. I like (in C) FLT_EPSILON or DBL_EPSILON, which are the difference between 1 and the smallest representable value greater than one, in IEEE 754 single- or double-precision floating point representation, respectively. Alternatively, if you're dealing with values far from 1 (such that precision is noticeably affected), doing the same specification, but with the goal value instead of 1, works well.

Anonymous
Hi Jedi

Now that I have MLG editing powers, is it OK to edit answers to include a link to run the code in an online interpreter?
I don't want to step on any toes or anything but I see some answers every once and a while where it would be nice

"MLG"?

major league gaming

2:17 AM
I don't know; you could ask on meta.

Okay, just posted in the sandbox. Let's see how long the bot takes...

Ooh new challenge

So... dropsort. Do you think it merits a question here?

@Sp3000 Alright.

Wow I was dividing some numbers by 10^x in Mathematica to get rid of the 0s on them

> Dropsort is what is known in the computer science field as a lossy algorithm. It produces a fast result that is correct, but at the cost of potentially losing some of the input data.

And I was just looking at this one and guessed 10^54 and it got all the 0s off without getting rid of any other digits
I guess that was a hole-in-zero

Haha, nice!

0

Mathematica Range: <= 64 String: 368921261379020282513891270954327186982974673706213278032469400595412966847044520376177106248857169605480346489563721888158441477887340357265444593721230093185417136793217614909721283425696418258308730582895596139457963926138833267594357117764501504

Sadly it was not enough to get it below 32 bytes...
I actually have a feeling this might get cracked fast

2:24 AM
0

Code the Huffman! code-golf Or else he will huff and puff and blow your house down! That was completely irrelevant. This challenge is actually about Huffman coding. The gist of it is the frequency of characters in a given text is utilized to make its representation shorter. In other words, let...

Anonymous
@quartata I'd say no. Editing other people's posts is typically used to fix formatting/spelling and such. Adding a link to an online interpreter doesn't constitute a necessary edit to me - you should comment with a link instead.

@NewSandboxedPosts That was 7 minutes not bad
@Mego OK

Anonymous
carrot.jpg

That's taking a while to load.

2:26 AM
> Or else he will huff and puff and blow your house down!

So do you think I should post a dropsorting task?

Anonymous
@El'endiaStarman imgur has been taking forever today

Anonymous
@SuperJedi224 post it in sandbox and see how it goes

@Mego The actual issue is that it's a .webm or .gifv, but those don't one-box.
....would they if I used !? Answer: nope.

Anonymous

Anonymous
2:29 AM
Hmm

hi
wow, 9 stars on my stars

@Mego Okay, I'll do that later.
Anyway, I've got to go for now.
Bye.

Anonymous
Bye

2:54 AM
I'm seeing LaTeX equations flash in and out of existence... o_O

Anonymous
@El'endiaStarman story of my life

I'm trying to develop a chrome extension
to do just that

Anonymous
LaTeX?

Anonymous
You mean like TeXEverywhere?

2:55 AM
I'm using one.

Well that would explain why you see it too
I'm trying to use this as a way to learn some javascript

Anonymous
Err, TeX The World

Anonymous
Is gud

2:56 AM
$$\int_0^R r^2dm$$
Yes! I got it to work!

Anonymous
Neato

@GamrCorps *is tempted to replace that dm with dr...*

lol

Anonymous
flags as nonsensual

pffft!

2:58 AM
Now if only we could have this in challenges, just would have to change the operators to something non-code.

0

Lossy Sorting (Implement Dropsort) code-golfsorting Dropsort, designed by David Morgan-Mar, is an example of a linear-time "sorting algorithm" that produces a list that is, in fact, sorted, but contains only some of the original elements. Any element that is not at least as large as the maximum...

Congrats @quartata!
4

wow
neato!
Its even more impressive that it is 1000 on the dot.

Anonymous

3:02 AM
:P

/me considers suspending TheDoctor if he types that symbol or the word "star" again, for the millionth time
6

@AlexA. Option B was φ as in bee, right? The fahyl was just a joke.

/me wonders whether @Doorknob really uses IRC or is just pretending

Anonymous
@TheDoctor IRC? Is that a Nethack clone?

3:06 AM
I do use IRC :P

@AlexA. its pronounced "fi" (like "fly" without the 'l')

Anonymous
φ φ fo fum I smell the blood of an Englishman

@Mego >.> irc is like 40000000000 years old

correction: fee φ fo fum I smell the blood of an Englishman

Oh hey I missed my 1k rep congratz

3:07 AM
congrats again!

Thanks!

Anonymous
@TheDoctor I was making a joke because @Doorknob and his Nethack love

@TheDoctor some people.....

Anonymous
@TheDoctor I bet Mathematica has a builtin for that
3

3:09 AM
^

Anonymous
carrot.jpg

Anonymous
I'm trying to be a faster carrot than @Dennis but it's hard

recently i found out that mathematica has a lot of builtins that, the first time you use them, download the code from wolfram servers

Anonymous
:o Dennis why did you change your avatar back

so you don't have a million things you'll never use in your mathematica
that's kinda cool

Anonymous
3:10 AM
Yay lazy evaluation

@Mego Nobody seemed to be getting the reference anyway. :/

Anonymous
@Dennis You explained it and I still didn't get it

I got the reference :/

Anonymous
You should photoshop a pumpkin on Dennis's head or something

better yet: make him orange

3:11 AM
everyone is pumpkin

@Mego I rest my case.

Anonymous
@Dennis tbh that's probably more on me than you

my dog found out that he really like to eat pumpkins. He ate several of our jack-o-lanterns :/

Anonymous
My brain is like

So many stars on the star board...

Anonymous
3:13 AM
"Write a proof about optimal ingredient picking for n different ingredients to make pies with k distinct ingredients? No problem. Understand jokes/pop culture references? hurr durr"

He is just one person. You need several more people for statistical significance

@Dennis not anymore :/

I still see them.

carrot.jpg
2

your screen is bigger than mine

Anonymous
3:14 AM
Hey @TheDoctor what's your favorite pathfinding algorithm that uses heuristics to improve performance?

<s>i dont really use search algos</s> i'm a dog, i sniff

The Doctor doesn't need to search for anything; he knows the location of all things at all times.

Anonymous
Because the answer should be A-star
3

OK, now the stars are gone.
3

@Mego Dijkstra's. Now what? :P

Anonymous
3:16 AM
@Doorknob Dijkstra's algorithm doesn't use heuristics, which is why I had to explicitly mention heuristics

it doesn't?

Anonymous
Nope

There are so many words in here I don't understand:
4
2 mins ago, by Mego
Hey @TheDoctor what's your favorite pathfinding algorithm that uses heuristics to improve performance?

A* is lame. You should try a red giant.

@Mego my nose

3:18 AM

Anonymous
@Dennis You have a weighted acyclic digraph, and you want to find the shortest path between two nodes. Dijkstra's algorithm does that. A* does that too, but uses heuristics to hopefully do better. A* is identical to Dijkstra's in the worst case (when the heuristics are wrong/non-existent), but on average is much faster.

*crickets*

Hey @Dennis, in CJam, is there any shorter way to turn a string array into an integer array than this: ["1""2""3""4"]{i}%?

No one got my joke?

3:20 AM
@GamrCorps :i

@Dennis thanks!

@Mego If I didn't understand pathfinding algorithm and heuristics to improve performance, I'm not going to understand weighted acyclic digraph... :P

3:23 AM
I seem to have misplaced my carrot.
6

Topologists aren't concerned with improving pathfinding performance heuristically. All of their graphs are weightless, cyclic, and trigraphic.

ELD5 (Explain Like Dennis is 5)
3

> All of their graphs are weightless, cyclic, and trigraphic.

just like YO MAMA

3:24 AM
i'm going to run out of stars before tomorrow :/

20 mins ago, by Doorknob
/me considers suspending TheDoctor if he types that symbol or the word "star" again, for the millionth time

sorry

Just a reminder. :P

Anonymous
@TheDoctor I'm going to run out of stars before I go to bed :P

3:25 AM
@undergroundmonorail rekt

I will never, ever run out of stars. ಠ_ಠ

Darn, I ran out of stars for today...

*mlg airhorns*

ohhhhhhh

Thomas the Dank Engine

3:25 AM
@AlexA. You can always pin.

WHERE YOU AT? WHERE YOU AT? WOMBOOOO COMBOOOOOO

dew n doritos
mum get the camera

https://www.eff.org/issues/tpp >> http://cms.fightforthefuture.org/tpp/
"The Trans Pacific Partnership includes provisions that would lead to extreme Internet censorship and undermine democracy and national sovereignty. I demand that my government oppose this agreement and refuse to sign."
^ that should be pinned

i've always enjoyed the wombo combo because of the yelling, basically, but now that i play melee it feels almost sacred
like i get it now

Anonymous
@Dennis A graph is a collection of nodes and vertices connecting those nodes (usually in a 2D plane). A digraph (or directed graph) is a graph where the vertices only go one way - A->B does not imply B->A (where in an undirected graph, all vertices are two way: A<->B). A weighted graph is a graph where the vertices have weights associated with them, usually representing the cost to traverse the vertex.

Anonymous
3:28 AM
@TheDoctor Will it ban code golf?

maybe

Wombo combo will always have a special place in my heart. Melee is the only SSB. All others are imposters. drops mic

boom

@Vɪʜᴀɴ oh wus dis

3:29 AM
büm

Oh hey its TeaScript.

@Mego So far I'm with you. Still not sure how it's related to A★ though...

Anonymous

Anonymous
Is it supposed to work?

This is going to sound dumb but are there any shorter ways of printing aside from the implicit final result printing @Vɪʜᴀɴ

3:33 AM
print

@quartata uh nope. not yet probably should of thought of that sooner

Anonymous
@Dennis Pathfinding algos try to find a path between two nodes, preferably with minimal total weight. Dijkstra's algorithm is a fairly simple one. The A* algorithm is an improvement upon Dijkstra's, allowing heuristics to be given that improve the speed of the algo.

ah OK.

2

I am rocking the star board right now.
2

3:35 AM
me 3
ish
Dec 10 '14 at 15:26, by Martin Büttner
@TheDoctor he refuses to change his name to Snowbolt though, which makes all of us very sad. :(

This is pretty big for me, considering that I reached 15k rep before the Talkative badge. :P

Anonymous
@Dennis do you understand the pathfinding stuff now?

I think I get what pathfinding is, but I guess I'd have to read a couple of things before understanding the part about heuristics.

3:43 AM
@Dennis You sat in brooding silence amidst a bombardment of CJam upvotes.

@Dennis Heuristics is basically just picking a choice out of at least two that's probably better.
In the case of A*, the heuristic is distance to the goal. So if a choice moves you towards the goal, it's probably a better choice than one that moves you away.

Anonymous
^ basically that

Anonymous
Dijkstra's algo works similarly to a depth-first search

Anonymous
Where it explores a path until the cost is greater than a potential other path

Isn't Dijkstra more like a BFS?

Anonymous
3:48 AM
Heuristics allow you to say that certain vertices are probably more optimal than others, so it tries those first

It looks at the nodes which are closest to the start.

Anonymous
@feersum tbh it's kind of somewhere between both

With unit weights, would it not be exactly a BFS?

Anonymous
Yes

Anonymous
But non-unit weights muddy the resemblance

Anonymous
3:50 AM
Actually yeah it's more BFS than DFS

Anonymous
Fancy Dijkstra's algo gif:

Anonymous

Anonymous
And A*, with heuristics supplied such that more distance from start is better:

Anonymous

You should have started with the GIFs. :P
2

Anonymous
3:55 AM
Yeah I get that a lot

Anonymous
Both algos try to find a path that minimizes f(n) for node n, which is the cost to travel to n

Anonymous
(from the start)

Anonymous
Dijkstra's calculates f(n)=g(n), where g(n) is the best path it has found so far

neat little interactive a* thing

Anonymous
A* uses f(n)=g(n)+h(n), where g(n) is the same as in Djikstra's, and h(n) is the heuristic estimate of the actual cost

Anonymous
3:58 AM
The GIF above uses h(n) = dis(n), where dis(n) is the Euclidean distance from the start

Anonymous
So long as h(n) is less than or equal to the actual cost, A* will find the shortest path, with at most as many steps as Dijkstra's

Anonymous
With h(n)=0, it's identical to Dijkstra's

Anonymous
My OOP question can also be solved with graph theory, by making a connectivity matrix

Anonymous
Anyway, after that fascinating lesson on pathfinding, I'm going to bed

Good night!
And thank you for ELI5.

4:30 AM
Recommended YouTube video for me: "Cat Thug Life - Ultimate Cats Thug Life Compilation!"
ಠ_ಠ
10 hours ago, by Alex A.
Like one time on Facebook I joking said #thuglife and now I always get Tupac ads.
Apparently it carries over onto other sites.

If I needed a reason not to use Facebook, this would be it.
6

1

Given two points A and B, find the angle from line AO to line BO about point O where O is the origin ((0,0)). Additionally, the angle may be positive or negative depending on the positions of the points (see examples). Input will be points A and B, and may be given in any convenient form. Output ...

@NewMainPosts ....I should probably implement trig functions in Minkolang.
sin and cos at the very least. Their inverses too.