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seen Mar 7 '13 at 11:03

Jun
19
awarded  Editor
Jun
19
revised Solution for equation system with piece-wise defined functions
added 46 characters in body
Jun
19
answered Solution for equation system with piece-wise defined functions
Jun
15
comment Solution for equation system with piece-wise defined functions
It does not consider the else case of Piecewise, does it? Then, I am not quite sure how to differentiate if the submitted function is defined piecewise. And finally, I would really like to know how I got conditional answers from Solve (or NSolve, not sure) that one time, because that Solution would be much cleaner.
Jun
15
comment Solution for equation system with piece-wise defined functions
No, I definitely need piecewise defined functions. Strictly speaking, this is exactly on of the cases (but not the only one), where I need this function. Want I am trying to do is writing a Module, where you input a "surface" and the starting point and direction of a light beam, and it calculates the light path upon potentially multiple reflection. All in 2D, so curves are enough.
Jun
15
awarded  Promoter
Jun
15
comment Solution for equation system with piece-wise defined functions
I would prefer a general solution, but if nothing else comes, I am willing to give the bounty to an answer that solves the problem for the case where one curve is a straight line and only the other curve is arbitrarily continuous. Also, the first crossing point in a given direction from a defined point on the line would be enough.
Jun
5
comment Solution for equation system with piece-wise defined functions
Hm, this does not consider the "else" case of the Piecewise and it makes the whole thing specific to Piecewise functions. I don't fully understand 1) Why my code does not work, especially numerically and 2) What I did successfully yesterday. Unfortunately I deleted the test code, integrated this into a module and now it stopped working.
Jun
5
asked Solution for equation system with piece-wise defined functions
Jun
5
awarded  Commentator
Jun
5
comment Derivative from the left and right
Great, I thought so :) My functions are not two crazy, mostly piecewise defined straight lines or short polynominals, so both ways should work just fine.
Jun
5
accepted Derivative from the left and right
Jun
4
comment Derivative from the left and right
I think this should do the trick, thanks.
Jun
4
comment Struct equivalent in Mathematica?
This answer is basically what I also do, when working with models in different situations. However, I am often facing one problem: Some values may depend on other values (for example lambda->512, k->2 Pi/lambda). As they may not ALWAYS depend on those values, I cannot integrate them into the model. Until now I just cascade lists of rules, but that is not very convenient. Any ideas?
Jun
4
asked Derivative from the left and right
May
23
comment Shaping/simplifying equations in a certain way
Although it does not seem to be the way to go, this was an interesting thing to learn. Thanks
May
23
comment Shaping/simplifying equations in a certain way
Oh :) I just looked at "Options" :) Thanks again that made a huge difference again.
May
23
accepted Shaping/simplifying equations in a certain way
May
23
comment Shaping/simplifying equations in a certain way
First, thanks a lot, I got it! However, and that may sound stupid: The only option in my documentation is Modulus? o_O Whats the "Simplify option?" Additionally as another complement, that was not evident to me: Collect[expr,Exp[q_]] also works. This is very important for mè because due to the complexity, I do not know x in Collect[expr,x]. Why is Collect not mentioned in the manual page for Coefficients, for example?
May
23
asked Shaping/simplifying equations in a certain way