@Szabolcs, are you around?

You use the graph functionality a lot, right? I am just trying my first thing now and having trouble already

For starters, this seems like an ugly bug, right?

Graph[{1 [DirectedEdge] 2}] // ConnectedGraphQ gives False, but if I first show the graph in the front end by running gr = Graph[{1 \[DirectedEdge] 2}] (without suppressing the output) and then do ConnectedGraphQ[gr], then I get True

@Rojo It's a bit like Schroedingers cat... If you don't look, how will you know whether the graph is connected or not? :-)

@halirutan Star

Man, this is really awful..

Especially the difference between

g = Graph[{1, 2}, {DirectedEdge[1, 2]}];
ConnectedGraphQ[g]

and

g = Graph[{1, 2}, {DirectedEdge[1, 2]}]
ConnectedGraphQ[g]

Right

I was having trouble with a simple but more complex thing. Now I bumped into that and I don't feel like trying anythingn else

@Rojo I'm throughly fed up with the graph related functionality of Mathematica. It's broken in so many ways, they know it, and they simply refuse to fix it.

I rarely get any useful feedback from WRI regarding graph-related functions, the developer behind it seems to be very cynical.

Somehow graph display and graph processing are weirdly intertwined, which doesn't sound like such a good design ...

One of my pet peeves is how NeighborhoodGraph is unusably slow unless use with GraphLayout -> None. It's slow because it computes the layout, which is totally irrelevant when all I want to compute is the neighborhood. The developer at WRI insists that NeighborhoodGraph has to compute the layout and refuses to fix this function.

In the meantime most people have no clue why this function is performing so badly, they have no way of guessing what is going wrong, and likely they just assume that Mathematica is crappy software. Which apparently is true.

@Szabolcs Crappy design

What do you use for graphs?

You leave MMA completely or did you bind something?

@Rojo If I should guess...

github.com/szhorvat/IGraphR

@halirutan :)

OK, it's not a crappy program, I still like Mathematica, and I still use graph functions. igraph has bugs too. But Mathematica clearly has too many. Ever since this functionality was added in v8, it's been the buggies area I use.

It's -17 C outside and our heating started to give up. It's been running constantly yet the temperature is dropping. It's now 18 degrees inside. The heater is blowing about 20-21 degrees air.

Hope it won't drop too low by morning.

These American apartments are not very well built and have almost no insulation ...

@halirutan @Szabolcs and others. Are anyone aware of how to run a git command via Run/Import? I'm struggling to point it to a specific project:

Import["!\"C:\\Program Files (x86)\\Git\\cmd\\git.exe\"
  -C \"C:\\workspace\\project\"
  log",
 "Text"]

gives no error but no log either

Ok, I know now, path which is after -C should not be escaped. Still interested in explanation, though.

@halirutan This reminds me of a lecture video on Youtube on quantum gravity, multiverses and whatnot by Arkani-Hamed. One of the top comments to the video was complaining about physicists' wrong attitude towards cats. (Schrödingers' cat was maybe mentioned once.)

Once again I lost my faith on any sensible self-criticism on Youtube comments...

@kirma Youtube comments are always hilarious..

It's 14 degrees in the house now.

@Szabolcs Can't you repair the heating?

Or turn on the oven in the kitchen and close all doors so that you at least have one room warm?

@halirutan can I ask something basic? :P

@Kuba if it was basic, you wouldn't ask, believe me :-) But go on, shoot.

@halirutan It's about command line so it is :)

@Kuba Yes, but you are on Windooze and there, everything is different

Is there any command line for dummies? I need basic stuff like, how to interprete "--relative[=<path>]"

I mean how usage messages translate to real syntax.

@Kuba [..] is always optional

It means you can give command --relative or you can specify the relative path with command --relative=/your/path

@halirutan Yes, now I know it. But to avoid further questions. Is this written somewhere?

@Kuba Let me see whether I find a nice how-to

@halirutan Thanks :)

@Kuba I guess the posix conventions is what you are looking for. But again, it isn't that hard really. There are only a few notations which are basically [...], <..> and .... Options have a short form like -a or -a <arg> or a long for --anOption

Look at the git man page. It is a very typical man page and even the one of gcc isn't more complicated.

@Kuba You have to understand that the SYNOPSIS is like the usage in ref-pages in the Documentation Center except that it never tells you what the command does.

It is just a formal description of the syntax. Everything else is described later in the man page.

@Kuba You do know what a man page is, yes?

@halirutan Sure :)

I think this is a (mildly) interesting question:

mathematica.stackexchange.com/questions/74172/…

Thanks, I know what it is but I wanted to be sure I'm aware of the syntax of synopsis. I "kind of" know this but I don't want to miss anything.

I could (1) vote to undelete it or (2) post it myself, perhaps after waiting a little longer to see if the OP does anything with it.

@Kuba Then read through the posix document I linked. It should be a very exact description.

@MichaelE2 post it yourself :)

@halirutan Yes it seems so. Thanks.

@MichaelE2 Or you are generous and edit the question so that it is written up a bit better and vote to reopen.

With this the OP will get some points.

@Kuba Feels like poaching... I don't think the issue is dealt with elsewhere on the site, at least not directly. (The function does not cross, i.e. not transversely, the contour.)

@halirutan Sounds good. It will have to be after I finish grading, though.

@halirutan I'm running the oven. I can't repair the heating. It's the landlord's responsibility and it's kept under a lock. I'm hoping they'll come soon and fix it.

@Szabolcs Sounds awful..

@MichaelE2 I don't think so, OP deleted it anyway.

What's a nice way of generating a list of n colors? I am coloring something with the colors, and it would help if the colors are somehow as different as possible to the human eye

Right now, I'm just getting a list with RandomColor[], and playing around with a RandomSeed[] to get a suitable list...

So there's a colorspace

that's designed so that the distance in it

smth like Table[ColorData["Rainbow", i/(n-1)], {i,0, n-1}]

is similar to the "common" human perception of color distance

(c) mathematica.stackexchange.com/a/27784/536

That's what ColorDistance uses by default

yet another several related examples: mathematica.stackexchange.com/q/21130/536

@Nakilon that's a nice idea, but if n gets even mildly large, I get different shades of say red. It's to difficult to tell the different shades of red apart

@Juho Are you intending this to be color-blind safe too?

@Searke Not necessarily. I am actually coloring edges of a graph and then looking at the edge-colored graphs

I am making the edges thick, but still it would help if the colors were, in some sense, far apart from each other

So, the LAB colorspace does this

I would look at the documentaiton on LABColor

Oh, thanks! I will...

Hrmm! I want a StringMatchQ that could say answer to the question of "if the string being matched would have continued, could there have been a match?"

@kirma Isn't that always the case?

(except for patterns with EndOfString or StartOfString)

@Rojo No, it needs to match exactly.

@kirma But couldn't the string always imaginarily continue to match after its end? I probably misunderstood, do you have an example?

@Rojo Well, you could expect StringMatchQ["x", "xy"] to have a chance to continue matching (but fail matching because not enough characters, but StringMatchQ["y", "xy"] has no chance of "having a match in the future."

@kirma Something like futureStringMatchQ[x_, y_]:=StringMatchQ[y, x<>"*"]?

x matches y if y is x+stuff?

(or x ~~ ___ instead of x<>"*")

@Rojo Well, that works for this specific case, but I would it to work for nontrivial regular expressions...