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visits member for 2 years, 3 months
seen Nov 21 at 8:58

Feel free to correct the grammar mistakes in my posts.


Nov
21
comment NDSolve and strange “nonlinear coefficients problem”
As to the last question, have a look at this and this.
Nov
21
comment Having difficulty with NDSolve
possible duplicate of Solving System of Nonlinear with Three Differential Equations
Nov
20
comment NDSolve and strange “nonlinear coefficients problem”
Using Method -> {"MethodOfLines", "SpatialDiscretization" -> {"TensorProductGrid", "MaxPoints" -> 151, "MinPoints" -> 151, "DifferenceOrder" -> "Pseudospectral"}} in SIM1 also leads to the u[x, t] = x solution.
Nov
20
comment Maxwell propagator problem 2D
I've also used 1D/2D FDTD code as example in many of my questions, for example this, you can have a look.
Nov
20
comment 1/2D FDTD problem
@MariusLadegårdMeyer is right, though the code contains improper Compile usage. Using fdtd[[2]] instead of hx in ListPlot will give you the desired result.
Nov
20
comment Maxwell propagator problem 2D
And you have mistakenly used Dot as Times, moreover, how can you "implemented only the first equation for Hy"? FDTD is a leap-frog finite difference scheme! You need to first understand what FDTD is before programming. To learn FDTD, you can read this book.
Nov
20
comment How to get a more compact form of this probability calculation?
@hengxin It's OK to wait 24 hours or even longer before accepting so your question may attract better answers :) . I added a ErlangDistribution approach, have a look.
Nov
17
comment How to get a more compact form of this probability calculation?
Network is a bit slow today. See my answer.
Nov
17
comment How to get a more compact form of this probability calculation?
I think your program is wrong. In your program, a3 and a4, s4 and s5 are independent, but actually they're not, a3 is part of a4, s4 is part of s5!
Nov
17
comment How to solve this probability symbolically or numerically?
@hengxin You can use FindSequenceFunction: FindSequenceFunction[Table[(μ^m (2 λ + μ))/(2^(m + 1) (λ + μ)^(m + 1)), {m, 5}], m]
Nov
15
comment Calculating integral by Romberg Algorithm
I'm not surprised that @DanielLichtblau is confused. It'll be better to keep your original code in the question.
Nov
15
comment Calculating integral by Romberg Algorithm
@ShutaoTang Oh, I should have read the document of Flatten more carefully. Thanks for pointing out.
Nov
14
comment How to extract a list of available Method-s
possible duplicate of How do I get a list of allowed values for an option?
Nov
14
comment Calculating integral by Romberg Algorithm
@ShutaoTang Oh, I think that besides some minorities, Chinese always put family name ahead. For your new question, you should notice that InputForm and PrintPrecision and NumberForm etc. Only control the display of the number, it doesn't influence Precision nor Accuracy. Nevertheless, calculate with MachinePrecision and control the display with NumberForm etc. may be more close to what your text book has done, significant arithmetic is the secret recipe of Mathematica anyway.
Nov
13
comment Series expansion of InterpolatingFunction obtained from NDSolve
Method -> {"FixedStep", Method -> {"ImplicitRungeKutta", "DifferenceOrder" -> 5}} is also available, there should be more, I guess.
Nov
13
comment Series expansion of InterpolatingFunction obtained from NDSolve
Seems that InterpolationOrder in NDSolve can only be set to All.
Nov
11
comment What is the best way to flatten a linked list with lists as values?
@Mr.Wizard Yeah, they all display as intended.
Nov
11
comment What is the best way to flatten a linked list with lists as values?
What font do you use? The AngelBracket simply doesn't display correctly in my browser.
Nov
10
comment Is it possible to pipe the output of EvaluationMonitor to Excel?
Well, are you sure it's the same region?: Column@{RegionPlot[x^2 + y^2 < 0.2828427 && 0.1 < x < .2 && 0.1 < y < .2, {x, 0, 0.2828427}, {y, 0, 0.2828427}], ParametricPlot[{r Cos[\[Theta]], r Sin[\[Theta]]}, {r, 0.1, 0.2828427}, {\[Theta], 0.0, \[Pi]/2}]}
Nov
6
comment A Stupid Question Maybe - EigenNDSolve
In fact you can consider modifying the source code a little. (Add a Rationalize[……, 0] somewhere etc. )