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Jan
8
comment Why does table behave differntly in mathematica compared to wolframcloud?
@george2079 And this actually happens in v10.2. So this syntax of Do isn't as popular as that of Table 囧.
Jan
7
comment Best way to emulate MATLAB's bsxfun using Map and similar functions
Here comes the winner!
Jan
7
comment How do you remove noise to detect just the human voice?
I tried to improve the format and expression, but since I'm not familiar with this issue, what I can do is quite limited and I might have made mistakes, so feel free to roll back if you don't like my edit.
Jan
7
comment Why does table behave differntly in mathematica compared to wolframcloud?
@march You're right, according to the legacy document, it's actually added in v10.3. Thanks for pointing out, edited.
Jan
7
comment Finite Difference - heat generation in a square (square within a square)
@Valentin Feel free to continue to ask in the comment if you still have difficulty in understanding the solution :)
Jan
6
comment Behavior of ArcTan when two zeros are given as arguments
Well, coming back to this answer after playing with Mathematica for 3 more years, I noticed that I didn't fully understand @J.M. 's comment at that time. Now I'm quite sure this answer is not perfect and has even made several mistakes (e.g. mixing up MachinePrecision and $MachinePrecision, not noticing N[0, 16] still returns an exact zero rather than an approximate zero with precision 16). Oh, now I can answer the "why doesn't ArcTan[0, -0.] return -Pi/2" question myself, it's because -0. evaluates to 0., which I think is a not-hard-to-accept default behavior.
Jan
6
comment Continued fraction with different numerators
You are looking for Fold?
Jan
6
comment Second Order ODE (Bessel Function) with a dependent variable in the BC
I guess BC2 is actually $u'(x)=m u(x)$ when $x\to 0$?
Jan
5
comment DSolve—different solutions for same set of equations using different symbols?
@MichaelE2 There're at least 3 related questions in this site (notice those links in the comments): mathematica.stackexchange.com/q/25182/1871
Jan
4
comment VERY slow to solve a nonlinear equation involving matrix eigenvalues
Maybe I'm thinking too far ahead, but is the matrix coming from differential equations? If so, have you looked at DEigenvalues and NDEigenvalues?
Jan
4
comment The first Chinese word always becomes a question mark, what is wrong with my mathematica?
Does the solution here help?
Jan
4
comment Symbolic integration of SphericalBesselJ
@vsht Well, "backslide" is just a tag (coined by me) to mark those backslides/backsets/degenerations/degradations/regressions/retrogressions in newer versions of Mathematica and I think this issue definitely fits into this category. I guess WRI just claimed it's not a bug, right?
Jan
3
comment For-loop function problem
@m_goldberg The syntax of Table has been modified silently in v10: mathematica.stackexchange.com/questions/99500/…
Jan
1
comment System of Four First Order Equations for Double Pendulum using RK-4 - Code Improvements
“I am also quite aware of the built-in Runge-Kutta methods, but I need control over everything and the built in methods were not letting me do that (I could be wrong)” I'm afraid you're indeed wrong, as far as I can tell, the "ExplicitRungeKutta" method of NDSolve is quite open and transparent and it allows you to control over every thing. Have you read this and this answer? (They are just quoting from the document actually.)
Jan
1
comment Unexpected behavior from Accuracy
Well, actually I think there's a more general issue behind this and many other precision-related question in this site, that is, the rule for precision (not sure I've used the correct terminology) of Mathematica is just similar but not the same as that we used when we calculates with pencil and paper. Maybe we need a community wiki or something for this.
Jan
1
comment Unexpected behavior from Accuracy
@george2079 You should really make your comment an answer.
Dec
31
comment Why this upvalue doesn't escape from Sum?
@jkuczm ……To be honest, I didn't notice the influence of HoldAll. (I thought upvalues can always escape from Hold!) You can elaborate this to an answer.
Dec
31
comment How many ODEs can NDSolve handle?
Please provide a minimal example that can reproduce the issue.
Dec
30
comment How to input superscript without using Superscript[x,y]?
This question should be marked as a duplicate of mathematica.stackexchange.com/q/33672/1871
Dec
30
comment How to input superscript without using Superscript[x,y]?
@JasonB The question is indeed confusing at the beginning, but now OP has clarified it in the comment: he/she needs Superscript rather than Power. They're totally different, though looks the same in the front end. BTW you may also feel this post interesting.