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Feel free to correct the grammar mistakes in my posts.


36m
comment What is the efficient way to code Successive Over-relaxation (SOR) method in Mathematica?
Can you please explain what's SOR method and add your code?
1d
comment periodicity of a solution of ndsolve pde
Well, OK, then are you sure it's periodic? BTW, I think if you correct the typo in your code after it's pointed out by others, you can avoid those downvotes.
1d
comment Integrate does not accept my integrand expression
Oh, I didn't notice this, the syntax is incorrect, it should be 0 < u < 2 Pi, and after adding this, the integration becomes slower and I don't want to wait, but deleting the assumption for u yields the same result as the {u, 0, 2Pi} case.
1d
comment Integrate does not accept my integrand expression
Nothing special, I just ran your code. Seems that my result of Integrate is different from yours. Have you tried the code with a fresh kernel?
1d
comment Integrate does not accept my integrand expression
For your new piece of code, v8.0.4 gives {0, -(1/2) π ((Infc + Refb) Cos[u] + (Infb - Refc) Sin[u]), DirectedInfinity[-I Sign[Infb]], 1/2 π ((Infc - Refb) Cos[u] + (Infb + Refc) Sin[u]), 0}.
1d
comment Integrate does not accept my integrand expression
@HaoWu Check my edit. BTW, my friend still can't get f Pi/m with his Maple 18 even with the assumption m!=0, can you provide the code?
1d
revised Integrate does not accept my integrand expression
added 677 characters in body
Apr
21
comment Mathematica examples with many calculations?
@Nasser I think 2. means a step-by-step solution. If so, for your simple example, this method is enough: c = With[{a = 2, b = 0.9, d = 4, e = 2}, (d e^b/a) // HoldForm]; Print@c; c // ReleaseHold. Also check this post for an extensive discussion.
Apr
21
comment Integrate does not accept my integrand expression
Seems that I've made some kind of mistake Saturday. Today I retried Assumptions option inside Integrate and it gives the correct result. See the answer for details.
Apr
21
answered Integrate does not accept my integrand expression
Apr
19
comment Integrate does not accept my integrand expression
The integration with Assumptions option inside Integrate just finished and it gave back the input 囧. A friend of mine has also tried Maple 18 but it gave back the input (Maybe it's because he isn't good at Maple? ). Also, when m = 0, the result isn't actually f Pi/m but f Pi (1 - 2 Log[R]). As to the integration without assumptions, the results of that from 0 to 2 Pi and from -Pi to Pi seem to be the same when Element[m, Integers], and though a direct substitution of m won't work, we can get a simplified result for a specific m with Limit.
Apr
19
comment Integrate does not accept my integrand expression
You're right. Seems to be a bug at least to v8.0.4. BTW, if I introduce the assumptions with Assumption option of Integrate, the calculation seems to last forever. Maybe you can report it to Wolfram company?
Apr
19
comment Integrate does not accept my integrand expression
v8.0.4 evaluates to 0.
Apr
19
reviewed Approve suggested edit on Different Poincaré maps for same Equation
Apr
19
accepted If doesn't compile if its output is the output of Compile?
Apr
18
comment If doesn't compile if its output is the output of Compile?
@OleksandrR. In fact it's that question that motivate me to ask this one (I've noticed this behavior for some time), I read it but still failed to notice it's an identical issue 囧.
Apr
18
asked If doesn't compile if its output is the output of Compile?
Apr
18
comment Linear interpolation over 2 variables
It's hard to give suggestions without a specific code sample, can you add one?
Apr
17
comment Derive a PDE from other PDEs
In addition, to avoid downvotes I suggest you to show your specific effort on solving this rather than just pasted the question here and vaguely said you have "read some material". BTW, you forgot to give the definition of $\rho$.
Apr
17
awarded  Revival