Reputation
57,220
Next tag badge:
139/100 score
18/20 answers
Badges
2 90 227
Newest
 bugs
Impact
~766k people reached

Jun
10
comment Bessel functions and ListContourPlot
Your formula should have the radial coordinate $r$ where $x$ appears in the Bessel function. I'm voting to close because this is not a Mathematica-related problem.
Jun
9
comment Can I enter the traditional form for Binomial as input in an expression?
@Guesswhoitis. I added your suggested notation for the Stirling numbers.
Jun
9
comment vector product defined on kronecker delta
Maybe the following will be better suited for your ultimate goal (this is just a guess): How to define an orthogonal basis in the right way?
Jun
9
comment Derivative of contour in ContourPlot
@AlexeyPopkov I got confirmation from Wolfram that this is a known bug.
Jun
9
comment Coefficients in multidimensional polynomials
Yes, that's really a matter of taste, but I thought Extract looks more natural than Apply[Sequence,{2,0,1}+1] - I think people should use Extract more...
Jun
8
comment Can I enter the traditional form for Binomial as input in an expression?
@Guesswhoitis. I think so - should I try to add that? I'll have time later today...
Jun
6
comment Laplacian and DiracDelta
@LeonidShifrin Yes, I think so, too. The idea to define Abs' as HeavisideTheta does work in other contexts for me, e.g. when proving Green function identities. But it didn't quite give the desired result in this case.
Jun
6
comment Laplacian and DiracDelta
The result is zero because Mathematica produces results that are generically true if you don't add any assumptions. For almost all $\vec{r}$, the result is correct.
Jun
5
comment Derivative of contour in ContourPlot
Your answer does what I would have expected my answer to do - probably DifferentiatorFilter in my answer invokes LowPassFilter (+1).
Jun
5
comment Vertical rulings for a cylinder
@Guess who it is. Thank yo for the edit...
Jun
5
comment Derivative of contour in ContourPlot
I have filed a bug report on this [CASE:3355498]. Let's see if I hear back from them.
Jun
5
comment Derivative of contour in ContourPlot
Strange - I directly used the irregularly spaced data as you provide them in the question, and got no error message. I am using Mathematica version 10.1.0 on OS X. Would be interesting to find out what other versions do.
Jun
5
comment Derivative of contour in ContourPlot
Yes, I think that's actually a bug. I see no reason whatsoever why the y-axis is scaled the way it is.
Jun
4
comment Reducing a system of vector equations
Closely related to the futility of $Assumptions here : Inequalities with assumptions and constraints.
Jun
3
comment Mathematica and special functions
Closely related: Incorrect results for elementary integrals when using Integrate. Unfortunately the solution there (Integrate`InverseIntegrate) doesn't work in general. Also related: Why does Mathematica give the wrong answer when integrating?.
Jun
2
comment Singularity Messing up Scale in Vector Field
Related: I'd like to display field lines for a point charge in 3 dimensions
Jun
1
comment Python-style plots in Mathematica
Two closely related posts (only regarding the color vs. lightness issue): Is there an easy way to use Matteo Niccoli's perceptual color maps for 2D plots in Mathematica? and Create colour with given lightness value.
May
31
comment Reduce applied to vectors doesn't work right?
@Bichoy Yes, I'm just making up a guess here - maybe totally unrelated... for Equal, the same could happening as with UnEqual, only we don't see the difference...
May
31
comment Reduce applied to vectors doesn't work right?
@SjoerdC.deVries I think another possible reason for the change is that after version 8 equations between lists were allowed in DSolve, and there they must be interpreted by threading Equal over lists - that's what is automatically done here, too.
May
31
comment Compress uses too much memory and sometimes crashes the Kernel
@OleksandrR. Yes, it all depends what kind of "expressions" are of interest. But for the example, my method works much faster than Compress, and I can also crank the data size up to $10^8$ without encountering a crash either in compression or decompression. In that case, Compress/ Uncompress aren't able to compete with HDF5.