Wolfram Mathematica

belisarius

00:18

ha!

acl

00:37

what next?

belisarius

@acl The question answered by "42"

acl

@belisarius as are all questions

belisarius

that's far too optimistic

damn trying to build the polygons connecting the "floors" . Very difficult

acl

I remember reading an article by Michael Berry where he claimed that, if I calculate the trajectories of two particles (classically I guess and in some box, but I don't remember), and recalculate them after shifting an electron at the end of the universe, the time it takes for the new trajectories to differ so much from the old ones that a collision is missed is...

42s

obviously he made it up, but I laughed so much it hurt

@rm-rf since you use os x you might know: I have an animated gif. If I open in preview, it displays the frames as different images. if I use quicklook (ie select the file and press space), the animation plays. how can I open the gif in something and have it play the animation rather than show all the frames as distinct images?

halirutan

01:09

Hi. Some native English speaker here?

acl

@halirutan no, but maybe I can help

halirutan

@acl In German the word "Zusatzfrage" (additional question) has a slightly different meaning than only additional question

It kind of suggests that the Zusatzfrage is far more hard to answer and honor to the one who can solve it.

acl

@halirutan OK yes I don't know what the closest analogous expression is (I know what Zusatzfrage means)

halirutan

Is there another English term than "additional question"?

@acl Ok.

No problem. I decided anyway to not ask this Zusatzfrage for now ;-)

acl

maybe it doesn't exist. like there is no word for "frustration" in greek

Verbeia

02:21

@halirutan I don't think there is a truly equivalent word in English, but a version with a joking overtone would be "for extra credit, [....the question ]?

belisarius

02:44

@rm-rf look

The SE UFO

halirutan

@Verbeia Yes, that's what I was looking for..

rm -rf

03:08

gah! Another day ended at 195!

I have about 2 weeks worth of days now where I was just an upvote away from hitting the cap

belisarius

@rm-rf You should warn us before it happens

rm -rf

End of UTC day is an odd time for me on most days... I either have seminars or meetings or other stuff around that time.

Or I'll be scrambling to do something at the last minute

belisarius

@rm-rf Do you like my UFO?

rm -rf

Close the gaps ant it has my vote :)

(might not be easy)

belisarius

@rm-rf I like the gaps!

I made holes in the surface on purpose

rm -rf

03:17

aha

lol

@belisarius make it a little fatter and it can be a piñata

belisarius

04:14

@rm-rf look

rm -rf

05:20

@belisarius Can you put that (one half) in the hypnotoad's eyes? And make one eye out of phase with the other :D

belisarius

@rm-rf wait

with occluded borders

rm -rf

probably needs Lighting -> "Neutral"

belisarius

exporting

@rm-rf I'll give you the code

@rm-rf here it is

nope

@rm-rf here

NotebookPut@ImportString[Uncompress@FromCharacterCode@Flatten@ImageData[Import@ "https://i.sstatic.net/mH2tV.png","Byte"],"NB"]

rm -rf

ok, too much work :P

belisarius

nah, just fun

rm -rf

05:33

My comment here got 4 upvotes, yet I see no votes to close...

belisarius

@rm-rf Because you are right, it shouldn't be asked. But we shouldn't forbid it

rm -rf

It's just not a real question... how on earth would you answer something about mma 9 and windows 8 on ARM? Neither of them are released

It's not about censoring/forbidding anything.

belisarius

Damn! I'm beerless. The World is just worse now

@rm-rf Well, WRI has a very strong bias towards secrecy, but that isn't really a standard. Many companies publish their road months ahead

rm -rf

but you can't absolutely say if something will definitely run or not (which is what makes an answer) with neither of the products in the market.

belisarius

@rm-rf Again, you are authorized to speak that way because you know a lot about WRI behavior. I work (for example) with IBM software, and I'm aware months ahead of any change in platform support (being an inclusion OR exclusion). When you are planing heavy investments in hardware, that can save you millions

rm -rf

05:54

@belisarius Ok, I trust your judgment on this one. I know Sjoerd argued before that questions such as "Does mma 8 run on X" (and X is existing) should be allowed even though I felt they were localized at that time, but I guess they're fine. I do see your point about investments in hardware, though...

belisarius

@rm-rf Most probably, WRI releases that kind of info in advance to their big customers (and also the docs containing Internal`, Developer`, etc)

but they keep it outside the public domain

rm -rf

I wish they were more frequent with their updates and bug fixes... it's terrible to have to wait for a whole major version update for some bugs to be fixed

I like MATLAB's predictable twice a year cycle

belisarius

@rm-rf Matlab is an order of magnitude easier to test and mantain

Mma is becoming a monster. That's no good

2

just look what's happening with the Graph functionality. Hope they homogenize the whole thing in R9. It drives me nuts

rm -rf

@belisarius Not really buying that... when an operating system, which is probably much more complex than mma can release at a regular schedule (twice a year), I don't see why mma can't.

It probably helps that one has millions of users volunteering their free time to develop it, whereas the other takes place behind closed doors with only a small number of folks working on it..

belisarius

@rm-rf An OS is quite simple to maintain. It's subsystems are completely decoupled. A database is more complex. Mma (I guess) is a nightmare

rm -rf

06:04

Why is mma more of a nightmare than an OS? (Serious question; I haven't the faintest clue)

belisarius

@rm-rf Because if you change anything in the evaluation loop, every function is impacted. Think how coupled are Plot or Reduce with the way the rewriting rules are evaluated

In an OS, the disk subsystem maintenance team could live in Mongolia ...

ALSO

and perhaps more important

there are 60 years of experience developing OSs

invested by the best minds in CS

the concepts are crystal clear by now

@rm-rf anyway, too late here. going to bed

rm -rf

@belisarius Alright, good night!

fpghost

08:35

Is it possible to have Mathematica stop evaluation of a Module if it encounters an error and then dump out some of the local variables? e.g. in my module I NDSolve an ODE that takes maybe 30mins, then NIntegrate a function of that solution. Sometimes however NIntegrate gives errors like ::slwcon, and rather than just lose the ODE solutions that Mathematica has worked for, I would like the Module to dump them out (maybe to some global var) if an NIntegrate error is found

J. M.

09:30

@rm-rf So, how'd the LP thing go?

@halirutan the usual idiom I've seen is "question for extra credit".

Whoops, Verbeia said it already...

halirutan

09:57

@J.M. Yep, Verbeia already helped out ;-)

Luke Allen

10:49

guys how do you 'skin' or color the dialog boxes differently in mathematica? here is ugly default example: http://img7.imageshack.us/img7/8116/ca8eb3f632a8444eb8ff155.png

and here is beautiful one http://img197.imageshack.us/img197/7347/8032f66d3b674e719de7a34.png

acl

11:14

@fpghost the debugger can stop on messages and allow you to inspect the stack and local variables:

But I did not understand what you actually want to do so maybe this is not enough

belisarius

11:44

@acl Isn't it nice? :)

acl

@belisarius this is what it reminded me of

►

belisarius

@acl _They live by photosynthesis because they cannot feed on anything in this lake. _ I didn't know that jellyfish could do that. I wonder if it's true

acl

so do I...

Jellyfish Lake

Jellyfish Lake (, "Fifth Lake") is a marine lake located on Eil Malk island in Palau. Eil Malk is part of the Rock Islands, a group of small, rocky, mostly uninhabited islands in Palau's Southern Lagoon, between Koror and Peleliu. There are about 70 other marine lakes located throughout the Rock Islands. Jellyfish Lake is one of Palau's most famous dive (snorkeling only) sites. It is notable for the millions of golden jellyfish which migrate horizontally across the lake daily. Jellyfish Lake is connected to the ocean through fissures and tunnels in the limestone of ancient Miocene reef. ...

halirutan

@LukeAllen First you should know, that this is system dependent. On OSX it looks like your beautiful one per default:

Luke Allen

12:01

@halirutan thanks I figured it out by using controlsrendering -> "generic"

does anyone know how to write "any positive integer" symbol in mathematica im new

halirutan

@LukeAllen In what context do you need it?

Luke Allen

x / any positive integer

that's it

belisarius

@acl "The golden jellyfish are most closely related to the spotted jellyfish (Mastigias papua) that inhabit the nearby lagoons.[6] They are similar to the spotted jellyfish in that they derive part of their nutrition from symbiotic algae (Zooxanthellae) that live in their tissues and part of their nutrition from captured zooplankton.[7]"

Luke Allen

like as a display formula in traditional form

halirutan

@LukeAllen f[x_ /; (Element[x, Integers] && x > 0)] := x^2

Luke Allen

12:04

for explanation purposes

J. M.

@belisarius Aha, symbiotes. I was wondering just how could a jellyfish have chlorophyll...

...so, a bit like a good number of corals.

belisarius

@J.M. Yeah. Sounded stupid

halirutan

@LukeAllen This defines f for positive integers only.

Luke Allen

@halirutan why would you use that instead of just x / Z-+

i don't know the Z-+ in mathematica tho

belisarius

@J.M. Did you see the birth of jellyfish? It's impressive!

I saw it in a BBC doc

J. M.

12:06

@belisarius Oh yes, I was part of this group that did experiments on jellyfish and hydras once... neat stuff. Weird-looking, but certainly neat.

@LukeAllen ...well, Mathematica has no support for the $\mathbb Z^+$ notation, so we make do with what's there.

halirutan

@LukeAllen Do you mean only for displaying purpose?

Luke Allen

yes

halirutan

Like this

Luke Allen

im not doing any calculation

halirutan

J. M.

12:08

@LukeAllen If you want: f[x_Integer?Positive] := x^2

belisarius

@J.M. experiments on jellyfish and hydras ... I always wonder why biologists are not attracted by self dissection

J. M.

@belisarius I don't know either. :D

Luke Allen

x/[DoubleStruckCapitalZ]

J. M.

@LukeAllen x \[Element] \[DoubleStruckCapitalZ]

Luke Allen

thats what i got so far how do i make it positive? the other way didnt work

oh wait

J. M.

12:11

x \[Element] SuperPlus[\[DoubleStruckCapitalZ]]

Luke Allen

what is the element part for

J. M.

I was copying halirutan's image.

Luke Allen

about that, how did he paste an image in here

halirutan

@LukeAllen ok, here we go:

type:

x esc el esc esc dsZ esc

esc is Escape key

And for this

you type

Luke Allen

but what does element mean? I'm really new to math lol

is that wrong or something? looks best to me

J. M.

12:14

x \[Element] SubPlus[\[DoubleStruckCapitalZ]]

@LukeAllen You know some set theory, yes?

halirutan

Here we use this for saying element of

Luke Allen

no lol I got a C in high school algebra

halirutan

@LukeAllen look here

especially the notation

J. M.

@LukeAllen "a is an element of set B" means just that; you have this object "a" that belongs to the set "B".

halirutan

$user image$

Luke Allen

12:16

ok so that is the same thing as img254.imageshack.us/img254/9695/8d0ddd54a512440dba5f179.png right? just in a more math like form

x E z

and img254.imageshack.us/img254/9695/8d0ddd54a512440dba5f179.png

same?

J. M.

What's the slash supposed to be?

Luke Allen

division

all i need is for it to say "x divided by any positive integer"

J. M.

You can't exactly divide by a set...

Luke Allen

its not a set it's a variable?

i just used a random letter

like a^2+b^2=c^2

instead of a, b, or c i used xz

J. M.

So, say $x/y, y\elem \mathbb Z^+$

Luke Allen

12:19

omg

ok let me rephrase

38 / any count number (like 1, 2, 3, 4, 5, doing it one at a time not all at once)

instead of just saying 38, since the number can vary (but only one number) i used x as a variable

i'm trying to explain to my classmates how to solve for the least amount of smoke detectors in a room

the only way i know how is to do it through steps you have to repeat over and over, not smart enough to make it an algorithm

so lets say you're given a rectangular room that is 38 by 102 units

each smoke detector can cover a maximum area of 250, and is constrained by a^2+b^2=c^2 (c^2 is 500)

so you can stretch rectangles or use the 15.81 by 15.81 square

the best way to do it, we found out, is to divide the shortest side of the room by any positive integer

so 38 / 1

too big, it exceeds

22.3

22.3 is the max, because 22.3^2+1^2=499 or so

belisarius

smoke detectors cover a circle

Luke Allen

so we do 38 / 2 = 19

@belisarius not according to the code book which is what we design to

doesnt matter what real life is

J. M.

Yes, I've never heard of a smoke detector that isn't omnidirectional. Oh well...

Luke Allen

anyway 38 / 2 is not ideal, because it's not very close to 15.81 which is the biggest box

so we do 38 / 3 and get 12.67

this is closer to 15.81, barely

so we use 38 / 3 or 12.67 because it's closest to sqrt(250)

and divides the shortest side of the rectangle evenly

then we tile the smoke detectors across UNTIL

see look

sorry for the misalignment i was messy,

but you can see i tiled the first 5 detectors across, but then the last part was a slim rectangular area

so i used a different, elongated rectangle for that area

and instead of having to use 18 total detectors i could use 17

(matters more in larger rooms)

so im trying to explain this 'tiling by the short side first and then repeating from step 1 for what's left over) process

im not smart enough to make it into a one step formula

\!\(\*
StyleBox[
TagBox[
StyleBox[
DynamicModuleBox[{$CellContext`b$$ = 34.62365341186524,
Typeset`show$$ = True, Typeset`bookmarkList$$ = {},
Typeset`bookmarkMode$$ = "Menu", Typeset`animator$$,
Typeset`animvar$$ = 1, Typeset`name$$ = "\"untitled\"",
Typeset`specs$$ = {{{
Hold[$CellContext`b$$], 45., "degree"}, 0, 90.}}, Typeset`size$$ = {
520., {256., 264.}}, Typeset`update$$ = 0, Typeset`initDone$$,
Typeset`skipInitDone$$ = True, $CellContext`b$1182$$ = 0},
DynamicBox[Manipulate`ManipulateBoxes[

im not sure if pasted mathematica code works here but that is how i was able to do it because you can stretch the rectangle inside a circle (omnidirectional like you said) spacing requirement

belisarius

@J.M. Smoke gets in your eyes until you can't tell what a smoke detector is.

J. M.

12:31

@belisarius Eh, I'd rather have smoke on the water...

Luke Allen

maybe one of you is smart enough to figure out how to do this in less steps? XD

I've been thinking on it for about 2 weeks

and I know it's theoretically possible to shorten this down to a simple formula but idk wtf it would be

belisarius

►

belisarius

13:35

@J.M. I wasn't able to understand the smoke problem. He should try with beer instead.

J. M.

I sorta kinda zoned out after the diagram...

belisarius

@J.M. fully understandable

rm -rf

14:38

I too think this is NC and needs votes... anyone else?

J. M.

@rm-rf That makes three of us. I guess any mod vote to close at this point wouldn't be unilateral...

(though for now I just set it CW)

belisarius

@J.M. Voted to close

rm -rf

@J.M. I guess not, but I feel that community close votes have decreased in general (a lot of regulars are AWOL at the moment), so just trying to nudge some users here (and other 3k lurkers) to vote

belisarius

@rm-rf I dislike some subtle tones in his comments

rm -rf

That makes it two of us

I would've voted to close this one too

belisarius

14:47

@rm-rf You were happier as a plain user

It's raining ... questions

rm -rf

@belisarius Heh, naah. I'm not hesitant to close as a mod, but I've seen that when a mod does everything because of the one-click powers, the community slowly relaxes and reduces participation in janitorial tasks. I don't want that to happen, because 5 names on that list means a lot more than one with a diamond. But I do get a feeling that some people were more comfortable voting to close when there was an existing close vote and I usually got the first vote in if it was during my daylight hrs.

belisarius

@rm-rf I think mods need a "not binding" voting mode

rm -rf

@belisarius Looks like we have... puts on sunglasses... no escape from questions

@belisarius I do too, and so do many others (perhaps most of them), but it was asked and declined by Jeff long ago.

belisarius

@rm-rf yep. I am aware of that proposal. It isn't needed at all in larger sites, but here it could be nice. Anyway, I guess you could get pointed out for using one or the other mode.

@rm-rf I plan to post a question about using Resolve[] results as a domain for Piecewise. How does it sound?

J. M.

@belisarius Guy rubs me the wrong way, period.

belisarius

14:59

@J.M. "To rub" here is ... well ... if you like it

rm -rf

@belisarius I don't actually mind not having a single vote. I think in most cases, as a mod, a comment is just as effective. I've thrown in "possible duplicate" links in questions and some users agree and vote to close if they have 3k and others flag. Once it has a certain number, I cast my vote

I don't think the community would come at me if I closed something like this guy's question here... the hesitation/waiting period is because as I said, I would like the newer 3k users (who didn't have much chances of voting when the top users here were hyper active) to get more involved

acl

speaking of closing, am I the only one who finds this way too localized?

1

Q: FindMaxValue and FindMaximum - how to find GLOBAL maximum and not just LOCAL maximum

I will not be able to provide a simple minimum working example here as this seems to be very specific. I have an interpolating function which I substituted into a PDE and then plot said PDE at a certain time for x and y. I'd like to find the global maximum of this function. Finding the maximum ...

mathematical-optimization

belisarius

@rm-rf I wasn't aware we're getting "new" 3K users

@acl You're right, but. What can he do to find help? "General" methods for finding global extremes are surely going to pour down if he don't include the actual thing

Searke

New 3k users? Now I feel lazy.

belisarius

Sorry, I love it

I can hear it breathing

belisarius

15:29

@rm-rf Got an umbrella?

@J.M. remember the question I was going to post about using Reduce results as Piecewice domains. Try this:

f[x_] := Piecewise[{{-Cot[x] - Tan[x]/Sqrt[1 + Tan[x]^2],
Resolve[Exists[C[1],
Element[C[1],
Integers], ((\[Pi] + x > 2 \[Pi] C[1] && \[Pi] + 2 x <
4 \[Pi] C[1]) || \[Pi]/2 <
x - 2 \[Pi] C[1] < \[Pi])]]}, {-Cot[x] + Tan[x]/Sqrt[
1 + Tan[x]^2],
Resolve[Exists[C[1],
Element[C[1], Integers], -(\[Pi]/2) < x - 2 \[Pi] C[1] < \[Pi]/
2]]}}];
Plot[f[x], {x, 0, 2 Pi},
PlotStyle -> {{Thick, Dashed, Red}, Blue, Green},
Exclusions -> {Cos@x Sin@ x == 0}]

Great!

acl

@belisarius right,that's why I didn't vote to close it. but now he got his help, and I am not sure this question does much more than clutter up the place

belisarius

@acl Ahhh ... ok. you meant to close it after being answered. Agree.

acl

@belisarius well, that's what I was thinking anyway. I don't really feel all that strongly about it

belisarius

When in doubt ... let it be :)

acl

fair enough. I'm not totally convinced though.

rm -rf

16:34

hahaha, here we go!

J. M.

0

Q: Do you think moderators over-control posts?

Am I the only one that has the impression that the site is under too much control of moderators, instead of being more open to the users?

discussion moderators

rm -rf

0

Q: Do you think moderators over-control posts?

Am I the only one that has the impression that the site is under too much control of moderators, instead of being more open to the users?

discussion moderators

lol

J. M.

Wow, simultaneous! :D

@rm-rf Time to use those eyes of yours...

rm -rf

"Am I the only one..." yes, you are. We should reverse the classic breakup line and play it to him — "Honey, it's not me; it's you."

belisarius

@rm-rf Are you talking to me?

@Rojo Hi red one!

J. M.

16:38

I'd downvote, but it'd be awfully unsporting... >:)

rm -rf

Well his question has 3 close votes already... if it gets 2 more, it'll show him how those damned pesky moderators spoiled his... oh, wait.

belisarius

@rm-rf Power is a drug. Let's fly.

J. M.

@belisarius The trip is great, but the crash afterwards sucks...

belisarius

@J.M. I've heard that before

rm -rf

@belisarius Nah, power corrupts only those who never had it in the first place. Compared to the hypnotoad eyes, the diamond is nothing

Mathematica StackExchange (meta)

16:43

0

Q: Do you think moderators over-control posts?

Am I the only one that has the impression that the site is under too much control of moderators, instead of being more open to the users?

discussion moderators

belisarius

@rm-rf Sorry, brb. Downvotes call me

done

It feels better now

J. M.

@rm-rf "Alle befolgen die Hypnokröte" :)

Damn, and here I was thinking somebody was asking how to implement ridge regression in Mathematica... :D

belisarius

@J.M. hehe ... I was waiting for your answer

J. M.

I'll just say, thank Golub, Kahan and Reinsch for making SVD practical...

acl

17:28

when lyx crashes, it first pops up a window apologizing and ending with "Bye!"

I thought that was sweet

rm -rf

Never used lyx

J. M.

BTW rm... how'd that LP problem you had go?

rm -rf

@J.M. Oh, yes sorry I didn't respond to that ping earlier. Was busy then, but forgot about it later. No, I haven't had the chance to look at it yet... I have a talk coming up and was hacking together a few slides

btw, are you familiar with basis pursuit?

J. M.

@rm-rf Nope, I only heard it from you today. Looks interesting...

It looks like the sort of thing you'd tweak into an LP problem.

rm -rf

Yup... it is tweaked into an LP problem and mathematically, it should retrieve the exact solution. And as I said, it does... except, in the wrong order :D

Need to poke more though... which brings me to a related question:

Do you know of a way to initialize MATLAB and Mathematica to the same PRNG?

A custom one will do too. I'm not interested in cryptographically secure or robust PRNG... just one where I can initialize to the same seed and have both of them spew out the same set of numbers

J. M.

17:42

What version of MATLAB are you on, again? I seem to recall them switching the algorithm, but I forgot when...

rm -rf

I remembered your blog post on the TI RNG, so was wondering if you had something up your sleeve

@J.M. R2012a

Well, even though the algorithms might be the same, whatever internal initialization they use is different. For instance, using Mersenne twister on both with the same seed won't give you the same stream

J. M.

Yes, I tried to reproduce the stuff here in Mathematica; no dice...

mcg16807 could be done in Mathematica as the "LinearCongruential" option of SeedRandom[]; swb2712 seems to use the same algorithm as "Legacy". Otherwise, the other algorithms will have to be reimplemented in Mathematica.

rm -rf

Yes, I tried them all, but couldn't initialize both to the same stream. Oh well... might be a good way for me to learn to implement my own generator in both and self-answer a Q

Stack Exchange

Blog - Stack Exchange: Our newest team members: Diandra, Robert, Adam, Nicole and Casey!

Bethany Marzewski on October 17, 2012

In case you haven’t noticed, we’re growing pretty quickly over here at Stack Exchange. But just because they’re last doesn’t mean they’re least – so say hello to our newest hires!

Diandra Partridge, Office Manager

Denver

Diandra steps in as the office manager for our new Denver hub. A graduate of Amherst College, Diandra is happy to be back in her hometown as a member of the Stack Exchange team. Her current obsessions include (but are not limited to) Adventure Time, musical theater, and Tard the Grumpy Cat. …

J. M.

@rm-rf FWIW, that was relatively easy, since it's just a combined LCG. :) Implementing, say, the lagged Fibonacci generator is a bit tricky.

It doesn't help that both MATLAB and Mathematica are coy on how they're using the seeds they're given to warm up the generators...

The voting should be for the answers. Downvoting questions should not be allowed at all (another meta Q) There are no wrong questions after all. — NoEscape 4 mins ago

Clearly he is, contrary to his contention, new to this.

belisarius

18:03

@J.M. FAQs are hard to read

J. M.

@belisarius "Screw the FAQs! I have a problem I needed to solve yesterday! SOLVE MY PROBLEM, TWITS!!!1!"

belisarius

@J.M. Ok. spit it

J. M.

:D

(Damn, I do a fair impression of an entitled brat...)

belisarius

@J.M. I know you don't mean this. But brat : 2. A child of a career military person. ???

What is the noun for the child of a carpenter?

J. M.

@belisarius No; usually, for that sense, there's always an associated modifier: "army brat", "navy brat"...

Nobody really uses "brat" unmodified, in that sense of the word.

belisarius

18:17

@J.M. "SE brat"

rm -rf

@belisarius more like "forum brat"

belisarius

I always thought it was disdainful. Never thought of applying it to a child

rm -rf

@belisarius on the contrary, brat is always applied to a child or child-like behaviour

belisarius

@rm-rf OK. Thanks. I surely mistaken it for another similar word

J. M.

...it would certainly fit the toddler who was happily exercising his larynx at the supermarket aisle, for instance...

belisarius

18:29

@rm-rf Why don't mods just step aside from this? The community will take charge

rm -rf

@belisarius Should I delete it then? Was just pointing out stuff he can't see.

belisarius

@rm-rf He can't see it for a good reason

rm -rf

@belisarius heh, fair enough. Removed

belisarius

@rm-rf I think a mod action should be a "last resort". You don't need to expose yourself so often

J. M.

On the brighter side, he's actually somewhat more civil lately. There's still something about his tone, but at least it's not as brash as it was...

rm -rf

18:32

@belisarius You mean on main or meta or this specific question?

belisarius

@rm-rf I mean "exposing" everywhere. If the community is able to manage a problem, let them do it. If it escalates higher and higher, act swiftly and without debating-

George Wolfe

Is it ok for me to lurk here? ... Good ... but, but, Eden was not populated by frogs, wizards, breathing whatits

rm -rf

@GeorgeWolfe Most certainly :)

It is not private

belisarius

@GeorgeWolfe It's a forbidden Eden. But you may enter.

J. M.

@GeorgeWolfe We're sorta kinda nuts, but I think you can fit in... :)

rm -rf

18:37

@GeorgeWolfe It's better if you reply to messages instead of editing the previous one (which you can only do within the first 2 mins)... continuity is lost otherwise :)

George Wolfe

Ok. Yes, I feel that I am with other of my own kind ... finally.

J. M.

(...and if you want to edit your message to correct typos, press the up arrow key to start.)

belisarius

@GeorgeWolfe Are you a knot or a toad?

George Wolfe

I am a demiToad

acl

@GeorgeWolfe and let's not forget the fractal butterflies

(well, fractal butterfly so far, but I plan to reproduce)

George Wolfe

18:39

I am the spawn of an warty amphibian and a hairy strand of rope!

J. M.

@acl I shudder to think of what fractal caterpillars look like...

@belisarius So, he's knot a toad...

rm -rf

@acl I thought you had a kid ;)

belisarius

@GeorgeWolfe I knew I saw you a long time ago

George Wolfe

Yes, I have be spoken of before.

Sadly, demiToads are on the endangered species list.

belisarius

George Wolfe

18:51

It's nice to see that people still care about my kind. I must visit.

acl

@rm-rf but not a butterfly.

ok maybe I am missing something obvious, but: I have a list and wish to interchange two elements. what's the most direct way?

J. M.

@acl {l[[3]], l[[5]]} = {l[[5]], l[[3]]}

acl

@J.M. doh. thanks!

belisarius

cry swap ya craps

rm -rf

@belisarius "How do I detect a toad using Mathematica"

belisarius

19:03

@rm-rf Hey! that's my gold mine!

I went too far (With[{# = f[x_]}, argtra := Sin[x]]) &@argtra

rm -rf

@belisarius toadQ[id_Integer] := id == 5

belisarius

omg

gotta go. c u l8r

chris

19:37

quick trivial question: how to I get access to all questions I tagged as favorites? thanks

Ajasja

@chris Click on your name (to go to your profile) and then click on favorites

Hmm it seems this info is public

here you go: mathematica.stackexchange.com/users/1089/chris?tab=favorites

chris

@Ajasja ah... yes sorry it was right in my face!

Ajasja

@chris no problem, it happens

(happend to me today as a matter of fact mathematica.stackexchange.com/questions/13194/…)

P. Fonseca

22:34

Any news from the Wolfram Technology Conference?

Do you know if this year there's also the NDA for everyone?

Is this conference being tweeted or followed by any poster?

chris

22:48

@halirutan Following your code I managed to do what I wanted... !Mathematica graphics

not the post exiting plot on the face of the earth but... thanks again.

rm -rf

23:17

@belisarius You around?

@P.Fonseca Yves is supposed to be covering it for the site

belisarius

23:31

@rm-rf partially

halirutan

23:56

@chris Good to hear.

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