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Feel free to correct the grammar mistakes and unidiomatic expressions in my posts.

Can we improve the quality of posts with tag differential-equations?


13h
comment Boundary Value Problem Errror
And are you sure your equations and b.c.s are correct? It seems that it's just a ODE about t, but the b.c.s aren't relevant here at all.
13h
comment 4th-order Runge-Kutta method to solve a system of coupled ODEs
If RunnyKine doesn't appear in the comment under this question, then the "@" won't work. And why are you still adding whitespace between "@" and the name?
14h
answered 4th-order Runge-Kutta method to solve a system of coupled ODEs
15h
revised 4th-order Runge-Kutta method to solve a system of coupled ODEs
deleted 596 characters in body; edited title
15h
comment 4th-order Runge-Kutta method to solve a system of coupled ODEs
(Sigh…) Just found your code in the edit history. This time I've done the edit for you, please check what I've done carefully.
15h
revised 4th-order Runge-Kutta method to solve a system of coupled ODEs
deleted 596 characters in body; edited title
15h
comment 4th-order Runge-Kutta method to solve a system of coupled ODEs
After pasting your code here, select them and press Ctrl+K, or add four whitespaces before each line of code. Things like \[Eta] isn't unreadable for Mathematica user, when pasting back to the notebook, it'll get back to the normal greek letters, and if you want to make your code look better in this site (of course it's encouraged), use the link I gave above to convert those "unreadable" symbol to greek letters!
15h
reviewed Close Integrated Solution Graphics
15h
comment 4th-order Runge-Kutta method to solve a system of coupled ODEs
Just copy and paste (Ctrl+C and Ctrl+V under Windows), as you copy and paste any thing. BTW, if you add a white space before "@" and "xzczd", the reminder won't work. It should be "@xzczd".
16h
comment 4th-order Runge-Kutta method to solve a system of coupled ODEs
Select your code and press Ctrl+Shift+I before copying. And you can also use this to convert your code to make it look better.
2d
revised How to modify a PDE inside NDSolve according to an if condition
deleted 10 characters in body
2d
answered How to modify a PDE inside NDSolve according to an if condition
2d
comment How to modify a PDE inside NDSolve according to an if condition
Well, I still suggest you to add the missing b.c.s, though NDSolve gives an answer currently, it's not that clear what boundary is added.
2d
comment Delete duplicates by a criteria
And your syntax for DeleteDuplicates is even incorrect.
2d
comment How to modify a PDE inside NDSolve according to an if condition
Is the function f[t, y, x] or f[t, x] or f[y, x]? And you still miss 2 boundary conditions. (A rule of thumb for the necessary number of i.c. or b.c. is that it should be usually equal to the highest order of the corresponding derivative.)
2d
comment Complete definition of special functions in Mathematica
I prefer pressing F1.
Mar
25
awarded  Popular Question
Mar
23
comment How to accelerate my code?
@Purboo "I think I need to learn Compile first." - Before that, I suggest you to read the last paragraph of this answer. "Sometimes it is not easy to write code using functions like Apply, Map and Thread. " - Yeah, sometimes, but quite rare in my opinion, in most cases, it's just because you're not familiar enough with the coding style of Mathematica.
Mar
22
comment Coupled non-linear differential equations
@Ricoleto As mentioned above, it's just a result of trial and error. Sadly it seems not to be able to handle Tmax=10, and I haven't think out a corresponding solution yet. I think it might help if you add some background information about your equations to your question. BTW, I just noticed that the b.c. in your code is different from what you claimed in the text i.e. $m(0,t)=m(\pi L,t)=v(0,t)=v(\pi L,t)$, is it intended?
Mar
21
reviewed Approve Square both sides of an equation?