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seen Feb 22 at 16:07

Feb
14
awarded  Excavator
Feb
14
awarded  Organizer
Feb
14
revised Given a set of rotation matrices, is it possible to determine the rotation conventions employed?
The question has been stated more clearly in the title and in the body of the text. The matrices therein have been written in standard MathJax, converted from pasted Mathematica Code (this is not a Mathematica-related question). The conventions have been rewritten more conventionally.
Feb
14
suggested suggested edit on Given a set of rotation matrices, is it possible to determine the rotation conventions employed?
Feb
5
answered Discretize an ellipsoid given its semi-major axes and orientation
Feb
4
comment Discretize an ellipsoid given its semi-major axes and orientation
@RahulNarain Yes.
Feb
4
asked Discretize an ellipsoid given its semi-major axes and orientation
Oct
24
awarded  Necromancer
Oct
17
awarded  Critic
Oct
13
accepted Equivalence of integral and differential forms of transport equation
Oct
13
answered Equivalence of integral and differential forms of transport equation
Sep
30
comment Equivalence of integral and differential forms of transport equation
Please see my comment to Mark E's response above (the problem statement is in fact correct, but I have made a mistake in the proof).
Sep
30
comment Equivalence of integral and differential forms of transport equation
The problem statement is correct as stated. I made a mistake in the application of the limit. $V$ depends on time, and so I cannot pass the limit through the time derivative. The approach apparently is to expand $F$, take it to be constant on the infinitesimal volume $V$, and then pull it out of the integral. This should, in theory, give a term on the left-hand-side that cancels the remaining limit on the right. However, I still can't work it out. I will post as soon as I get it.
Sep
25
asked Equivalence of integral and differential forms of transport equation
Jul
23
comment 3d-diffusion equation in spherical coordinates (numerical), boundary problem
Depending on the boundary conditions, you may be able to identify $i = 0$ with $i = N-1$. What are the boundary conditions? Also, can you explain to me where the $i-1$ terms in the denominator come from in the discretization?
Jul
15
accepted Surface area element of an ellipsoid
Jul
15
comment Surface area element of an ellipsoid
That makes a lot of sense. I did not stop to think about using $g(u,v) = f(\mathbf{r}(u,v))|\mathbf{r}_u \times \mathbf{r}_v|$ because I had already computed $f(\mathbf{r}(u,v))$ numerically. The drawing I made on a napkin of a section of the ellipsoid in which the 4 points form a trapezoid is a compelling but incomplete proof of my claim; I am stuck at the part where I need to show that a plane is determined by four points...
Jul
15
asked Surface area element of an ellipsoid
Jul
13
comment Numerical Integration over 3D mesh.
@AlexanderGruber This is a surface integral I thought. I wanted to make sure she/he was integrating WRT area instead of angle or something, since she/he seems to want to use some kind of strange differential in #3.
Jul
12
comment Numerical Integration over 3D mesh.
I don't know if you're still looking for answers to this, but if so, what is $\Omega$?