@belisarius @R.M you convinced me on the derivatives question. Voting TL.

Quickie: how was it figured out that "LakeColors" is the default color scheme used by ContourPlot[] and DensityPlot[]?

@J.M. I remember a question about`Plot[], but for Relief` I can't find anything but an answer from @Szabolcs that takes the color sceme for granted

Perhaps you can use the same method devised to get the color scheme for Plot[]

@belisarius Yes, I'm familiar with that SO answer for figuring out ColorData[1] as Plot[]'s color scheme. I'll see if it's adaptable. Thanks!

you're welcome

@J.M. Try a bunch and see which one fits? :P

@R.M Hi toad!

With[{g = ColorData["Gradients"],
  p = Rasterize@
     ContourPlot[Cos[x] + Cos[y], {x, 0, 4 Pi}, {y, 0, 4 Pi},
      ColorFunction -> #] &},

 Pick[g, p /@ g, p@Automatic]
 ]

(* {LakeColors} *)

@J.M. ^^ :)

@belisarius Hi! I saw that... lol. All the easy rep ones come by when I'm asleep :P

Hibernating?

It's good in a way... it motivates newer users to participate

@R.M Huh, I thought there was a more creative method than brute-force... ;P

Unthankful

Though, as they say in the army, "if a dumb thing works nicely, it ain't dumb". So, thanks. :)

It's one of those damned Automatic rules that AbsoluteOptions does not retrieve

@J.M. I answered the rep group basis question.

@belisarius I saw and upvoted. I'm far away from home, so I don't have my copy of Cotton to check... but I know there's something in there.

no need to hurry to search the chemistry book on group theory :D

@R.M Oh, Automatic, what myriad mysteries you hide...

@belisarius Surprisingly enough, it did have a lot of math. Understandably, only a small portion of it was taught in grad school... ;P

@J.M. and AbsoluteOptions[] reports ... Automatic :D

Hell, I don't know of a book that has a better discussion of SALCs...

I guess i never met the right chemist. All near me hate maths only with different strength

Well, in all honesty, the other chemists consider me weird, so... :)

@J.M. No wonder

Ah yes, another memory of that group theory class: I remember having to explain to my mates how the translation to matrix format worked; linear algebra wasn't exactly part and parcel of undergraduate mathematical education back in the day...

...and how to properly use character tables.

@J.M. I remember a basic inorganic chemistry course I took where they were "teaching" something they named "least squares", but none of the people in charge of the course were able to do a derivative

@belisarius Yes, I distinctly recall multivariable calculus being an unfortunate omission in the curriculum as well...

Oh, by the way, just though of something with that group theory question: you could actually replace the Inverse[] with Transpose[].

@J.M. I think the problem is a kind of "tradition" that gets established in curriculums. If those who design the courses don't know something, it gets automatically excluded.

@J.M. Probably, but my GT is rusty, and I am too lazy to go and check if that is completely general. Also, some of the dimensions calcs in the "generalization" I posted as an edit are superfluous, for sure.

@belisarius That was what saved me in chemistry class in grad school... a few of us (non-chemists) had to take it with those who were good in chemistry. They'd all run circles around us in where the bond breaks, where the OH group attaches to, etc. But when it came to working with Arrhenius eqn, acids and bases, etc. they just couldn't figure out logarithms and exponentials (yay!)

@belisarius For the most part, the usual symmetry operations (reflections, rotations, inversions, roto-reflections) are representable by orthogonal (at worst, unitary) matrices, so ConjugateTranspose[] would be the most general method.

@R.M hehe ... seems that experience is universal.

@R.M Heh. :D

Yes, there is a bit more emphasis with the qualitative part than with the quantitatives for most branches...

@J.M. Darn! Now I have to go and check. brb

Time for a chemistry joke: Q: "What's the Avocado constant?" A: "It's the number of atoms in 1 guacamole"

(rimshot)

@J.M. Enjoy : schulich.technion.ac.il/faculty_member.php?id=20

See the book he published

"Non-Hermitian Quantum Mechanics",

ha!

@belisarius Hmm, very intriguing. I'm more interested in a physicist's reaction, tho. ;D

@J.M. You could find quite a few around :D

The nearest library has a copy; I'll have to visit tomorrow...

@J.M. Seems a smart guy

with broad interests ... to say the less

@belisarius You know, those people who say "all my matrices are Hermitian!!1!"

and your processes are reversible, and your ionization energies are tabulated, and ...

Well gee, if all the conditions were ideal, the math wouldn't be so exciting...

@J.M. If you like exciting (or excited) ideas ... en.wikipedia.org/wiki/Leonard_Susskind#Smolin-Susskind_Debate

@belisarius Ooh boy, the anthropic principle. Sticky.

hehe I've had a professor (a very good and renowned mathematician) who always referred to Susskind as "master chaos"

There was an intense hate between them

@belisarius "them" as in your professor and Susskind?

@J.M. Yep. My prof was the creator of integral Geometry cimm.ucr.ac.cr/ciaemIngles/…

Okay, he was a student of Blaschke. Interesting...

@J.M. He was not only a very good mathematician, but also a remarkable human being and a fabulous teacher

No matter what he talked about, you always needed hundreds of seats.

Standing room, huh? Lucky you, being taught by him. :)

@J.M. yep. it was a honor

hi all, this is somewhat of an announcement to the community at large

I am on the road until Wednesday evening (at a conference, in fact) and I probably won't be able to make it to the town hall debate

I will come by and check chat every now and then until Wednesday, of course, so if you have any questions for me feel free to ping me here and I'll answer them

@F'x Have you contacted SE folks?

the time window is a bit narrow… and it's not that I cannot connect now and then, it's that I cannot make any promise about coming at a given time

@F'x Ok! Have a nice trip!

@belisarius I'm in Edinburgh, and it's nice indeed!

thanks

oh yeah!

@VitaliyKaurov Don't be shy :)