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1:34 AM
@acl I'm older than a decade, and still here
 
 
5 hours later…
6:10 AM
Yet another question on geometric computation on v10: how to find (and controllably sample) sharp edges (and high curvature) on boundary regions, in general? I have my fears the answer at least with v10 is "choose one: generality, ease or efficiency."
 
6:39 AM
@kirma Sorry, I haven't even started looking at that functionality yet.
Can any v10 Windows users reproduce the problem I describe here?:
0
A: Error when attempting to save Notebook. Cause and solution?

Mr.WizardFor the aid of anyone else who runs into this issue I seem to have figured out the compounding factors necessary to recreate this problem. Create a Windows directory C:\foo\bar Save arbitrary Notebook example.nb to this directory Using the Option Inspector add to NotebookPath exactly: "C:\\foo\...

 
 
4 hours later…
acl
10:25 AM
has anybody tried to implement adding automatic SyntaxInformation from usage strings?
 
acl
11:19 AM
@belisarius OK that's a bad analogy. You should be ashamed of yourself for making it.
 
11:50 AM
Mr.W will have 100.000 rep soon :)
 
12:35 PM
"It appears that native support for the Klingon alphabet has been removed from version 10."
3
Eh...
Mandatory in scientific computing. :)
 
 
1 hour later…
1:46 PM
DSolve can be really slow sometimes. Try this eq = a*D[y[x], x]^3 + b*D[y[x], x]^2 + c*D[y[x], x] - y[x] - d == 0
Timing[DSolve[eq, y[x], x]] but you would have to wait 1-2 hrs to get the answer !
 
2:04 PM
@SjoerdC.deVries
I don't really know. Not really my "area" so to speak. You'd have to ask Wolfram Technical Support and god knows there might some bizarre system underneath it all that's not succinctly describable. Or not.
 
@kirma removed after complaints from Babylon 5 fanboys
 
2:44 PM
@OleksandrR. Did you follow the thread on the slow startup? Some progress is being made.
@OleksandrR. @halirutan Do you guys have an opinion? It should be safe, right? mathematica.stackexchange.com/questions/54962/…
 
@Szabolcs do you have the link? I would try to find it again but the Community site is too slow
 
@Szabolcs thanks
@Szabolcs I managed to make the startup be much quicker by disabling the start screen and just opening a notebook. Then it's down to v9 startup times. But as soon as you show the start screen it's 40 seconds of 100% CPU and "formatting notebook contents" and there is high CPU usage and hanging for notebooks other than the start screen as well (especially the docs)
Seems like these experiences are common to many in the W|C thread
 
3:14 PM
There's a new large functionality area in v10: regions‌​. We should settle on a tag for this because more and more questions are getting asked and not all of them are properly tagged.
Shall we use , an existing tag? Or [tag:regions]? Or make a synonym of ?
Some people use which is probably not a good tag for this.
 
3:27 PM
What are "supported devices" for FindDevice and friends?
There are example devices such as RandomSignalDemo. Are they easily implemented, is it documented and I can't find it yet?
 
4
Q: What devices are supported by the connected devices framework?

SzabolcsOne of the new features in v10 is support for connected devices. How can I find out if a particular device is supported by Mathematica? Is there a complete list? Is support being added continually? The documentation says: Many classes of devices listed in the Wolfram Connected Devices Pro...

No complete answer yet.
 
@Szabolcs Thanks
 
@Rojo Just today I noticed there is documentation for developing device drivers... I don't remember the URL though.
 
Yes
@kirma tutorial/DevelopingDeviceDrivers
@Szabolcs tutorial/DevelopingDeviceDrivers
 
@Szabolcs "mesh" is definitely overspecified for computational geometry. And "regions" is also a bit questionable for general "computational geometry".
 
3:31 PM
@kirma I agree. Yet some of the questions related to this are not strictly computational geometry.
 
It doesn't help the situation that there is some regions functionality already in earlier versions, and it actually tends to be integrated with new stuff.
 
Also, there's both and . What's the difference?
I don't have the energy to write this up on meta today ... I think I'll go back to work for a while :)
 
Hah.
I didn't even know there's computational-geometry...
 
We also need to decide what we should do with the version-10 tag. The version-9 tag is not for features that were new in version 9, and I would like version-10 to have the same role for version-10 as version-9 for version 9. But this is not at all how it is right now.
 
Yep...
 
3:53 PM
There's no default shortcut for inserting a comment, right?
Alt+/ should do that when nothing is selected
Insert (* *) with your selection inside
 
@Rojo Here, Cmd+/ works (on Mac)
@Rojo Ah, OK. Not this does not work as nicely as in IDEA. It inserts (**) but it moves the selection the complete cell and doesn't leave the cursor inside the comment.
@Szabolcs I would say it is save because it is just the object that contains all the function pointers to the library functions.
 
4:10 PM
@halirutan Try it inside some code and not at the end
For example, type x y, then move the cursor between them
Right before the y
 
@Rojo This behavior is not consistent :-(
It's different when you use arg1 arg2 or Sqrt[ arg1 arg2 ]
 
@halirutan I have a code that calls several Listable and parallelization->True compiled functions, so needs multiple processors for parallelization. I want to execute this code for different RandomSeed using ParallelDo. If I have 30 processors and 5 RandomSeed, How do I tell it to use 6 cores for each ParallelDo iteration?
 
@brama I'm not sure I would do that. If your compiled code already runs parallel, why don't you use only Do? Don't forget that using ParallelDo will introduce additional overhead and it might slow your overall approach down.
 
4:26 PM
@halirutan but the marginal benefit for the code execution after certain number of processors is not great and I was wondering if I can better utilize the extracores for Do
I want to at least try it and see if it's worth doing it...
 
@brama Everything you need to know can be found here
13
Q: Parallel compiled functions running on parallel sub-kernels

halirutanQuestion Why is it, that compiled, Listable, parallel functions which work perfectly fine on the main kernel, do not run in parallel on sub-kernels? Details First Example Let me give a first example. I compile a function $f:\mathbb{R}\to\mathbb{R}$ which is a simple sum of sine-functions with...

 
@halirutan Will go through it. Thank you.
 
4:46 PM
@Pickett Please remove them from posts that don't need it... I've been untagging them whenever I see it. As you say, it doesn't make sense to tag every new question with and it's easier to control it now than when it accumulates 200 questions
 
@rm-rf OK, will do from now on.
 
@Szabolcs meshes, voronois, discretizations, convex hulls, etc. -> . Intersections of lines, planes, half spaces, *Triangle and other shapes, etc. ->
 
Intersections of line segments are now easiest done through what WRI calls computational geometry. I think dividing will be tricky, unless it's pre-v9 (geometry) vs. v10-and-after (computational geometry) features. And of course, being knowledgeable of the distinction gets really hard in couple years.
By the way, what do you refer by "half spaces" ?
 
@halirutan Right. It is just not meant tob e used without a selection. But it's a waste
I'd love it to be like your IDEA
 
5:03 PM
Also, many other things that WRI calls "computational geometry" are not included on your definition. It's problematic if more or less uniformly organized (at least on documentation) topic under that specific name is split in the middle - but I couldn't tell what would be the right way to do it.
I might actually suggest discrete geometry as a tag, and purely symbolic variant as another.
But that causes troubles with tag history, and all that geometry that has definitely existed before v10. It doesn't help much that some primitives have dual roles in both Graphics and regions-based computational geometry!
 
@kirma I guess mma doesn't have a half space... I was just rattling some terms. In any case, a half space (in 3D) is the entire region on one side of a plane.
@kirma It's not a perfect demarcation, but what I wanted to convey was that things like SSSTriangle should not be tagged
 
@rm-rf I searched long for a half-space (without parametric/implicit definition) in new regions functionality. Surprisingly enough, I didn't find any.
 
@kirma lol, sorry about that. That's why I didn't use a function name :)
 
This division in the regard of SSSTriangle and friends vs. more complex computation makes sense.
@rm-rf I actually looked for it earlier on. I would have expected it to be an obvious primitive. :)
 
 
2 hours later…
6:54 PM
@halirutan. Do you know, why the first one searches for Real values for variables, but the latter for Integers?
g[x_]:=Plus@@x; vars=Array[x,3]; {sol,{points}}=Reap[CheckAbort[NMinimize[{Hold[t=g[vars]],And@@Thread@LessEqual[‌​3,vars,15]&&vars\[Element]Integers},vars, EvaluationMonitor:>Sow[{vars,{t}}]],ignored]]; points
g[x_]:=Plus@@x; {sol,{points}}=Reap[CheckAbort[NMinimize[{Hold[t=g[{x[1],x[2],x[3]}]],And@@Threa‌​d@LessEqual[3,{x[1],x[2],x[3]},15]&&{x[1],x[2],x[3]}\[Element]Integers},{x[1],x[2‌​],x[3]},EvaluationMonitor:>Sow[{{x[1],x[2],x[3]},{t}}]],ignored]]; points
 
@Mr.Wizard Happy 100K :)
2
 
7:10 PM
@Szabolcs or @Öskå do you have any ideas regd. my question above?
 
7:45 PM
@Öskå he's 20 points short!
 
@JacobAkkerboom I upvoted two of his answer and it didn't update.. :(
@brama No idea, I've never used Reap/Saw myself :) I didn't take the time to get into it :P One day I will
 
@Öskå hm, strange. Probably Mr.W sees the right number though :)
 
@Öskå ok..thanks
 
@JacobAkkerboom I was thinking that it might be due to the fact that he reaches the +100K, maybe there are some checks or I dn't know .. :(
 
@Öskå @JacobAkkerboom He has already hit the max for the day... upvoting anything won't help until the next UTC day :)
 
7:51 PM
Haha what a cliffhanger :)
 
@rm-rf Oh snap, because there is a max.., never reached the max :(
He could have managed to reach the max at 100K :D
 
I expect everybody is trying to upvote him. Now he will overshoot by a lot :P
 
@JacobAkkerboom He won't overshoot... all those votes have no effect except increase the score of the post.
 
ahah :D like *he needs +20, lets do that*
and nothing, only disapointment :(
That was my case at least :P
 
Ah ok. So he will have his screenshot :)
I wonder if he will go for 100K or for 99999
 
7:54 PM
@rm-rf He won't have the rep tomorrow?
 
@Öskå No. Only upvotes given tomorrow (before he hits the max) count
 
So at 1AM for me I will have to upvote :P
 
Apparently, Mr.Wizard would've had 116k if not for rep caps :)
 
Sounds legendary :P
 
Why is there a limit per day then?
@JacobAkkerboom He is a Wizard after all, it's only legitimate :P
 
7:58 PM
@Öskå to even the playing field... and to make you go home. They don't want you to burn out. You are useful to SE only if you keep coming back, not if you turn on all the boosters in one day and then fizzle out.
Don't forget that all these upvotes, rep caps, badges, etc. are social engineering tactics to make you use the site more in the manner they want you to. In return they provide value to us through the use of their software for free and helping you be a part of this community.
 
Aug 7 '13 at 13:46, by Mr.Wizard
(braggart warning) I may now happily retire from mma.SE: I'm a Legend in my own time. :D
 
I thought it was self-satisfactory only :P
Although I was wondering.., how do they make money?
 
@Öskå Ads on Stack Overflow (and some other sites), Careers.SE
 
@JacobAkkerboom So he is legendary :o
 
8:01 PM
@rm-rf AdBlock is so magic that I forgot there could be ads on here..
 
Hehe, me too
 
Anyway, I'm off to play now :) Have a great evening/afternoon :)
 
bye
 
cya Öskå (autocomplete spelling cheat)
 
@JacobAkkerboom You don't have the å? Your name sounds scandinavian :P
 
8:04 PM
Ah, no I'm from the Netherlands :)
Hmm it seems I can't enter any special character here
oh now I can.. suddenly
Öskå
 
:D
 
Well done ;o)
ik ben een app!
 
een app? hehe
 
Has anyone already started using managed library expressions? Is there a way to retrieve a list of all existing managed expressions in Mathematica?
 
8:05 PM
geen aap?
 
ja, that's all I know
aap*
 
Ok I'm out :)
 
Cu!
Öskå
 
aha, train train :P
 
8:06 PM
@Szabolcs I was kind of curious about this, but I haven't tried it yet
 
@JacobAkkerboom If you start working with them and want to talk about something, ask me. I'm already neck deep in :-)
I really wanted to have this feature ...
 
@Szabolcs thanks, it's always nice to ask questions. I must say I don't know the basics yet though. I keep confusing this mathlink-like expression sharing (like putting expressions on a link). I suppose that is the main thing I am interested in
 
 
1 hour later…
9:21 PM
0
Q: Implement settable properties

SzabolcsI am looking for advice on implementing the following. (It is possible that the answer is that it is simply not a good idea to do this.) I would like to have an object similar to FittedModel. Let's call its head Obj. Like FittedModel, it will have properties, e.g. properties = {42}; (* prope...

 
acl
@Szabolcs regarding your comment under the question; I spent an hour or se earlier today writing code to automatically add SyntaxInformation to a bunch of functions I have from their usage strings. This while I am supposedly sprinting to finish a paper, helping a collaborator debug a calculation of his and attending a few conference talks.
sometimes it amazes me that I ever managed to not procrastinate my way to starvation
 
@acl But I have fewer papers than you, which reminds me that I should really move on and just do it any way it works ...
 
acl
@Szabolcs that sounds good until you end up using the same codebase for a year. then those shortcuts like "../../dir1/dir2/file.m, hardcoded into 30 almost-identical .m files and intended to load the main codebase, come back to bite you
and why, you ask, would I have 30 almost identical .m files?
Why, because you are too lazy to get your code to read command line arguments. no, you just write another piece of code to produce modified .m files, tailored to each run.
then more code to produce the shell scripts that are sent to the queueing system
then even more to produce the shell script to submit the other shell scripts
very clever.
so now I don't dare move anything.
the lesson is, it really does pay off to make at least a token effort to structure your stuff and use the appropriate tools :)
but yes too much of that and you end up wasting your time
(but how would I know? I write mathematica code to produce mathematica code to produce shell scripts that send shell scripts to the queue, in order to run mathematica code; and all because I am too lazy to plan ahead)
you can imagine what happens when I return from eg a one-week break and have to get back into this mess
 
9:45 PM
I enhanced the random game premise generator. Instead of just "flea", "jacket", "roller-blades". It is: A flew with a jacket that helps him understand more about his identity, who is on a roller-blading team, and who has a moral objection to drinking blood. I'm thinking skating/jumping between hosts for action/exploration elements, and trade/strategy elements between flea colonies.
 
acl
@MichaelHale where did the identity bit come from?
 
I added three random samples from the plot and goal categories on tvtropes.org.
They were "quest for identity", "free the frogs", and "garage band".
 
Can anyone reproduce this?
 
10:02 PM
@Szabolcs I'm seeing ~.24 on v10 Windows
 
@MichaelHale Even on the second try? (First try is often slow)
 
Yes, several tries.
 
acl
@Szabolcs .mx does seem cross-platform compatible, even between v9 on Linux and v10 on OS X for matrices, as you mentioned a few days ago. How did you know?
 
@acl Somebody uploaded some MX files here on SE and I was surprised to see that I can read them.
 
acl
@Szabolcs OK so it's not documented anywhere
 
10:07 PM
@acl Not to my knowledge, but I'll ask.
 
acl
@Szabolcs OK, please let me know if you find out about any limitations etc
 
@acl It is possible that these files are only compatible sometimes. E.g. simple packed arrays might work, but not sparse arrays, graphs, or other more complicated atomic objects.
 
acl
@Szabolcs yes, that is what I am mainly worried about.
 
10:51 PM
@Mr.Wizard Wow!.. 100k.. congratulations.
 
11:05 PM
Is it me or is the chat-server slow in general? In needs several seconds when I reload the page.
 
acl
@halirutan seems as fast as usual here
 
@acl Hmm. When I switch rooms, the "Loading room.. just a few seconds box" appears for > 20s.
 
acl
@halirutan I just tried entering a randomly chosen room, and it didn't seem slower than usual. certainly not more than a couple of seconds
 
@acl Never mind.
 
@Murta Thanks! :D Still 20 points to go though.
Hello @halirutan and @acl
 
11:15 PM
@Mr.Wizard Hi.
 
acl
@Mr.Wizard hi
v10 and 10^5 rep almost simultaneously, not bad
 
@acl It's nice that MX is now (mostly?) cross platform, but I'd like to remind people (not you particularly) that it is a significant safety concern as it could execute any code and circumvent any in-product security measures you've attempted.
 
Can someone on v>8 try this code?
 
More votes please! I don't know whether the vote-count is significant or not but we all want the V10 highlighter on this site, right?
6
Q: Update prettify highligher for this site

SzabolcsMathematica version 10 has been released, with new functions and operators. The syntax highlighter on this site needs to be updated. The highlighter that is being used is already updated in the GitHub repo. The new version simply needs to be added to this site.

 
Apparently it gives this on v9.. :(
 
acl
11:30 PM
 
@acl You are on v9?
 
acl
no, v10
 
So I assume that it should work on v9 as well.
@GuineaPig it seems to work on v10, what did you break? :P
 
acl
that is one convoluted piece of code
 
Hi Öskå. I'm using version 9.
 
11:33 PM
@GuineaPig And I am using v8, so if it works on v8 and v10 shoudn't it work on v9? :P
 
Well, that is weird.
 
@acl Sorry, that's the only way I found to achieve this using GraphPlot :P
@acl Would you have v9 by any chance?
 
acl
@Öskå it wasn't a criticism!
@Öskå yes, let me check
 
@acl Me not english, me don't speak england language very good :P
 
The code from Öskå is absolutely marvelous.
 
11:36 PM
I'm still with V10 beta. Can someone check that this gives a warning message:
 
acl
@Öskå OK yes, "Switch is not a graphics primitive or directive" on v9
 
d = StringSplit["The quick brown fox"];
Map[Apply[d[[#1]] &, #] &, RandomInteger[{1, Length[d]}, 100]]
 
acl
@MichaelE2 not here, what warning?
 
@acl The function is not compilable and I get an error Compile::cpapot
 
acl, you got that error in v9??
 
11:37 PM
Guess it's been fixed.
 
acl
@GuineaPig yep
 
@acl @GuineaPig Blaaaaah, works on v8 and v10 but doesn't on v9 :( Can't help much :O
 
Alright thanks. @Öskå alright.
I'll try this code in different version.
That will be take some time though. :(
 
Or like I said, try kguler code, it gives the right graph as well
 
But kguler's answer has a same problem with your previous answer.
 
11:40 PM
@GuineaPig I cleaned the comments on my answer as well, I only kept the "wannabe" explanations. Since it's 1am I don't know if they make sense :P
i.stack.imgur.com/7mz2M.png looks correct to me
 
Check the edges {0,1}
it has same color, but it shouldn't be.
 
acl
@MichaelE2 this is not produced even if I switch the message on here
 
cause the blocks {0,1,2,3},{0,1,4,5} is different.
are*
 
@GuineaPig Right.., I didn't check the colours but the numbers of edges only. You could try to tell him/her that, I bet he/she will fix it :)
 
I told him now :)
 
11:45 PM
Does this work on v9 then? the "answer" given in the question.
 
@Öskå Yes. It works.
 
@GuineaPig blaaah, then it's my trick which is not working. But why would it work on v8 and v10 but not on v9.., doh.
 
@Öskå I should check some settings...
 
@GuineaPig If it doesn't work for acl it's not your machine or your settings :)
It's just a not working code in v9. I will take a look tomorrow, right now it's bed time :)
 
acl
@Öskå the error message is curious
 
11:50 PM
@Öskå I mean mathematica settings. It might a problem in there.
 
@acl the way I built my function is even more curious :P
 
acl
something different is happening with the evaluation. I played a bit with it but didn't understand what
 
@acl Thanks. It probably got fixed before the official release.
 
acl
@Öskå yes, very acrobatic
I wonder how it looks to someone not used to mathematica and its evaluation model
 
@acl That's the only way I found to deal with Switch[#3, something] knowing that something can't be a list.., if you have a better/clever idea feel free to update this :)
I prefer not wondering :P
 
11:54 PM
@Öskå I'm cleaning my comments as you said.
 
Not sure if this should be turned into a question (like: why is V10 25% slower), or if I should send it to WRI-support (without getting feedback), or if it is just a Windows and Linux issue (no access to Mac right now): Evaluating this Do[f[i, x_] = N[i] + x*i, {i, 400}]; First[Timing[Nest[f[55, #1] & , 1, 250000]]]in V10 is 25% slower than in V9. This is just a cut-down artifical example, but I see a slow-down of about 20% or more also in larger applications. I do find this weird. Comments?
 
acl
@RolfMertig you mean vs V9?
@RolfMertig (it is also ~25% slower on OS X also)
 
So, should we send a formal complaint? I mean, I am really upset. Or they send me a 25% faster laptop ...
@acl probably the cloud is the future and speed does not matter anymore on the desktop ...
 

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