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Aug
21
comment Nonlinear differential equation: numerical solution
@Mattia Udina My equation is different from yours. You may have a look into the paper here: arxiv.org/abs/1507.03128, Section 4, where you will see both the equation, the tips of how to solve it with Comsol (not straightforward) and the images of the result. Concerning your thesis, I can try to give you an advice, though you should have an official adviser for that. But I will not do the thesis (or its part) for you. I suggest that you discuss the situation with your official adviser and he should decide, what you should do in the situation taking into account that Comsol is expensive.
Aug
21
comment Efficient way to generate random points with a predefined lower bound on their pairwise Euclidean distance
What is sweep used within you function spread ?
Aug
21
comment Efficient way to generate random points with a predefined lower bound on their pairwise Euclidean distance
@kglr As in the comment to the Ives Klett's answer Graphics[{Red, Circle[#, mindist] & /@ scaledpts}, Frame -> True] reveals that there are overlapping circles with the radius equal to mindist. I have seen even combinations of 3 overlapping ones. They are rather rare though. I like the approach very much, nevertheless.
Aug
21
comment Efficient way to generate random points with a predefined lower bound on their pairwise Euclidean distance
This Graphics[{Green, Point[pts], Red, Circle[#, mindist] & /@ scaledpts}, Frame -> True] reveals that there are some overlapping circles, though only few. Thus, not all resulting points are distant enough.
Aug
21
comment Creating points that are remoted from one another beyond a certain threshold. Quasirandom sequance?
@Patrick Stevens Yes, I agree
Aug
21
revised Creating points that are remoted from one another beyond a certain threshold. Quasirandom sequance?
edited title
Aug
21
asked Creating points that are remoted from one another beyond a certain threshold. Quasirandom sequance?
Aug
19
comment what am i missing?
First, you should not include inequalities into your list of equation. Second, you have four equations with 5 unknowns.
Aug
19
comment Simplifying normalized eigenvector, taking into account the freedom to choose phase
You are right, its me, who missed something. Please have a look at the edit.
Aug
19
revised Simplifying normalized eigenvector, taking into account the freedom to choose phase
added 351 characters in body
Aug
19
comment Simplifying normalized eigenvector, taking into account the freedom to choose phase
No its me. I read sign and thought theta. Sorry
Aug
19
comment Nonlinear differential equation: numerical solution
Continuation: 2) According to your equation the kink width is about 1. So if you anyway solve the problem numerically, you may efficiently solve the it within the interval 0<=x<=10, no need to go to infinity. And finally, the problem of such a type (and more complex of this class) is, indeed, solvable. I did it using, e.g., Comsol
Aug
19
comment Nonlinear differential equation: numerical solution
Mattia, this is a kind of problems related to phase transitions I often solve. In terms of phase transitions theory your equation describes a round domain of the phase u=0 in the vicinity of the coordinates origin embedded into the phase u!=0 in 2D. Two things about it.1) It is the PDE technique that you need here due to the boundary conditions you use. However, presently Mma has no nonlinear solvers for PDE as yet. Its a pity, but that's how it is. So you need to go for a software that has such. That was a bad news. Now the good ones.
Aug
19
comment Simplifying normalized eigenvector, taking into account the freedom to choose phase
Well I only see that c v is zero at theta<0and is nonzero at theta>=0. Since a zero eigenvector is of no use, we are effectively left with the latter case.
Aug
19
comment Simplifying normalized eigenvector, taking into account the freedom to choose phase
What else did you mean by multiplying by sign(theta) ?
Aug
18
answered Simplifying normalized eigenvector, taking into account the freedom to choose phase
Aug
17
answered Using Simplify to perform substitutions
Aug
17
answered How do I center an item in a Grid?
Aug
14
comment Integro-differential equation
Let us formulate the question differently: How to treat this with Mma? Then it is not off-topic. Second, this equation is a time-dependent integro-differential version of Sine-Gordon. It should have a number of solutions, rather than a single one.
Aug
14
comment How to do algebra on unevaluated integrals?
@belisarius One might add such a construct h=Distribute[Integrate[g, x]] /. Integrate[k_, x] -> HoldForm[Integrate[k, {x, -Infinity, Infinity}]] // ReleaseHold and it will enable one to work with definite integrals. But the question is WHY it does not work for definite integrals plainly?