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Mar
18
comment Plotting: Magnetic field lines
You could do an interpolation of your data and then apply my answer posted here. But how to do the interpolation depends on the grid geometry and data density.
Mar
18
comment how can I bold the outline of conic section as the plane intercepts the cone?
@SjoerdC.deVries I'd suggest the OP clarify the question so as to not waste time with misinterpretations...
Mar
18
comment Problem using Rotation in Show
You can't combine 2D and 3D graphics within a single Show. It's either one or the other, so you have to apply the conversion to 2D to both objects.
Mar
18
comment how can I bold the outline of conic section as the plane intercepts the cone?
possible duplicate of About Slicing through Graphics3D
Mar
18
comment Font style in Mathematica matching \mathcal and \mathbf in Miktex
The boldface part is trivial: just make the input boldface and (if desired) toggle italic. The keyboard shortcuts for this are the same as in most other application but that depends on your operating system. Maybe it's best to refer you to this link: Mathematical Typesetting
Mar
18
comment Phase Portraits
Have you tried GraphicsGrid?
Mar
18
comment Time Zone Conversion
It's elementary. Just stick with terrestrial time.
Mar
17
comment Convolve does not get the correct answer
Thanks for the analysis in edit #3. I already upvoted you before giving my own answer... couldn't believe that I actually stumbled on a bug there.
Mar
16
comment Schroedinger eigenvalue problem in two dimensions (Harmonic Oscillator)
It's relatively simple: if you have chosen a length unit by specifying a in the code, you need to bring the kinetic-energy term into the form $-(1/2) d^2/dx^2$. To do this, you have to choose the unit of energy appropriately.
Mar
16
comment Convolve does not get the correct answer
@DanielLichtblau Thanks for taking a look. It's sneaky because the c in Erfc is easy to overlook, and with Erf it would almost be right (up to a sign).
Mar
16
comment Convolve does not get the correct answer
@DanielLichtblau We just noticed that this really is a bug in Convolve. My answer below evaluates to the wrong result in versions 8 and 10.9.5
Mar
16
comment Convolve does not get the correct answer
Your answer is probably the only one that works because Convolve in my answer is buggy. In that case, I think the question is actually a duplicate of Convolving/integrating problems.
Mar
16
comment Convolve does not get the correct answer
Right, this seems to be a huge bug in Convolve.
Mar
16
comment Transforming expressions in terms of Csc and Sec to expressions in terms of Sin and Cos
Although the goal here is a little different, I think the main issue is the same as in Mathematica Sec and Csc, and there probably isn't a better solution - I would love to be wrong, though.
Mar
16
comment Simplifying complicated fractions
Closely related: Why does Simplify ignore an assumption?
Mar
15
comment NDSolve: basic settings for PDEs
Your initial condition $\partial u/\partial t = 0 $ is inconsistent with the boundary condition $u=\exp(-t)$ at $x=0$.
Mar
15
comment Schroedinger eigenvalue problem in two dimensions (Harmonic Oscillator)
@andi I added the info that you were asking for (I think).
Mar
13
comment Reflecting lines in ellipses: speed up the code?
The title of the question contains "in ellipses" - but that's misleading if you want to allow exterior reflections.
Mar
13
comment Reflecting lines in ellipses: speed up the code?
(+1) because this is specially adapted to the ellipse and therefore very fast. My answer doesn't make use of the special properties of the ellipse and can be adapted to non-elliptical shapes. But in any case, the question was misleading.
Mar
13
comment mixing color of individual parts of a function in DensityPlot
@Mr.Wizard Seems like Mathematica is trying to remove gray areas from its syntax for grey areas.