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 Curious
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comment Package for symbolic computation of christoffel symbols and parallel transports in Riemannian geometry, given the metric
If you were a physicist specializing in general relativity, I would suggest xAct with xCoba for the Christoffels, but it requires extensive knowledge of differential geometry. There exist less complicated packages, but I have no experience with them.
Apr
23
accepted Express block matrix in terms of matrix basis
Apr
16
revised Express block matrix in terms of matrix basis
deleted 30 characters in body
Apr
16
comment Express block matrix in terms of matrix basis
Thanks, this is very close to what I was looking for. Please check my answer and feel free to add the changes I made to yours, so that I accept yours and delete mine.
Apr
16
answered Express block matrix in terms of matrix basis
Apr
16
awarded  Curious
Apr
15
revised Express block matrix in terms of matrix basis
added 8 characters in body
Apr
15
revised Express block matrix in terms of matrix basis
added 1113 characters in body
Apr
15
revised Express block matrix in terms of matrix basis
deleted 7 characters in body
Apr
15
asked Express block matrix in terms of matrix basis
Sep
5
awarded  Nice Answer
Jul
25
comment Result of Integrate depends on order of integration although the domain is rectangular
@Jens,@MichaelE2: According to The Lebesgue-Stieltjes integral, p. 118, absolute convergence implies that the order does not matter (Fubini's theorem). Nintegrate over the absolute integrand yields Numerical integration converging too slowly[...]. As I increase the upper limit, the integral seems to increase with always diminishing rate, which indicates that it converges. I'm not very knowledgeable about the intricacies of integration, as I'm a physicist. Apparently, I need to learn more...
Jul
25
asked Result of Integrate depends on order of integration although the domain is rectangular
Jul
24
comment Mathematica 10 fails to calculate integral that Mathematica 9 can handle
It is correct, thanks. I get three results of varying complexity, depending on the version of Mathematica, and v. 10 cannot solve this if I swap the order of the variables of integration. v.10 after swap and yours give the simplest results. Unfortunately, the simplicity of the result does not remain constant or increase as the version increases, and it is quite obvious that most built-in simplifications do not work for the result I quoted above. Is there a way to configure how Integrate calculates the result?
Jul
23
comment Mathematica 10 fails to calculate integral that Mathematica 9 can handle
Please disregard my previous comment. Mathematica 10 can find the integral if I change the order of integration. Mathematica 9 cannot find it in this case after waiting for tens of minutes.
Jul
23
comment Mathematica 10 fails to calculate integral that Mathematica 9 can handle
Now this is getting weird: in v. 10 I get 1/2 Mass (1/r1 + \[Pi]/(2 Rotation) - ArcTan[r1/Rotation]/Rotation + ( Rotation ArcTan[Rotation/r1])/r1^2), which is the correct result and is much more simple than that of v.9, even though I didn't use Simplify and nothing, that I'm aware of, changed meanwhile!
Jul
23
comment Mathematica 10 fails to calculate integral that Mathematica 9 can handle
@MitchellKaplan I didn't; @Öskå probably edited my question and replaced \[Theta] with $\theta$ etc.
Jul
23
comment Mathematica 10 fails to calculate integral that Mathematica 9 can handle
Now that I tried it without Simplify, Mathematica 10 takes twice as long as Mathematica 9 albeit without result. The problem is not that Simplify is time-constrained; it is that the integral cannot be calculated.
Jul
23
comment Mathematica 10 fails to calculate integral that Mathematica 9 can handle
I didn't, because it takes far longer in Mathematica 10 than in Mathematica 9 for this to return, which seems to be a bug, too.
Jul
23
asked Mathematica 10 fails to calculate integral that Mathematica 9 can handle