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Feel free to correct the grammar mistakes in my posts.


May
14
awarded  Nice Question
May
13
comment Do not understand expression returned by FullSimplify
@Kuba I guess OP is suspecting that Simplify has internally Integrateed the expression and then differentiated it.
May
9
comment Parallel computation of NDSolve and a problem
@yashar It's because ParallelTable has the attribute HoldAll, so those Subscripts are passed into it before changing into numeric values. When you use RHS2 to store RHS, evaluation happens, and Subscripts are removed, it's equivalent to use Evaluate@RHS inside ParallelTable.
May
9
revised Parallel computation of NDSolve and a problem
deleted 1 character in body
May
9
accepted How to make the code inside Compile conciser without hurting performance?
May
9
answered Parallel computation of NDSolve and a problem
May
8
comment How to make the code inside Compile conciser without hurting performance?
@OleksandrR. You mean what Leonid Shifrin has done below? :)
May
8
asked How to make the code inside Compile conciser without hurting performance?
May
7
comment Parallel computation of NDSolve and a problem
Possible duplicate of mathematica.stackexchange.com/q/14723/1871
May
7
comment Parallel computation of NDSolve and a problem
Where did you put your RHS2=RHS? just behind the definition of RHS or, just in front of the AbsoluteTiming[……]?
May
5
awarded  Announcer
May
5
comment Behavior of 1.2 ∈ Rationals changes in v9?
@Szabolcs OK……what about posting this as an answer so I can accept it?
May
5
comment Behavior of 1.2 ∈ Rationals changes in v9?
Hmm……I'm afraid that the second example isn't proper. Consider Element[IntegerPart[Sqrt[2]], Rationals].
May
3
asked Behavior of 1.2 ∈ Rationals changes in v9?
May
3
comment Parallel computation of NDSolve and a problem
Where's the definition of sysdim and A and matrix?
May
2
revised Changing Plot order for 3D printing
Add another solution
Apr
29
comment NDSolve - sampling for result during the computation
@drN OP has chosen method "FixedStep", so the step size can be controlled by StartingStepSize, I think MaxStepFraction and MaxStepSize will also work (haven't tested yet), but I don't know how to control time step size in more general cases (for example PDEs), too.
Apr
26
answered What is the efficient way to code Successive Over-relaxation (SOR) method in Mathematica?
Apr
25
comment Solving the Helmholtz equation in polar coordinates
DSolve isn't good at solving PDE, and this is just one of the PDEs it can't handle (at least now), see here for details. If your final target is to get a numeric solution, consider NDSolve. Also, you can refer to this answer.
Apr
25
comment NDSolve - sampling for result during the computation
Have you considered doing the simulation piece by piece i.e. first calculate {t, 0, 10^-4}, then {t, 10^-4, 2 10^-4} and so on?