7 votes
Accepted

Numerical solution to fractional PDE

There are several numerical methods to solve fractional PDE. In this case the best one could be implicit difference scheme described in this paper. The implementation is not so difficult compare to <...
Alex Trounev's user avatar
  • 43.4k
5 votes
Accepted

How to improve the speed of this numerical integration which includes calculations of large matrix?

There are many issues with the code. The main one is that it is looong and totally unmaintainable. Hint 1. I am pretty sure that that most of the matrix M1 is ...
Henrik Schumacher's user avatar
4 votes
Accepted

Numerical Solution for a Non-Linear Functional Fractional Differential Equation (FFDE)

This is fractional delayed differential equation (FDDE), therefore we can't use method described in my answer here. Instead of the Haar wavelets method we try to use implicit difference scheme ...
Alex Trounev's user avatar
  • 43.4k
4 votes
Accepted

What is the value of this integral?

You can get a result close to Maple's using the method "LocalAdaptive": ...
Anton Antonov's user avatar
3 votes

What is the value of this integral?

You may help MMA a bit by splitting the integration range into 3 pieces. The first one the easy piece from 0 up to near the peak, the second over the peak, where you also specify "Method->&...
Daniel Huber's user avatar
  • 50.3k
3 votes
Accepted

Numerical integral does not agree with analytic integral

Not a Mathematica answer per se, but just in case its useful, I'll expand on my comment under the question. Let's write the original integral as $\int_0^{2 \pi } u(t) \, \mathrm{d}t$ where $u(t)=t \...
chuy's user avatar
  • 11.2k
2 votes
Accepted

NIntegrate failed to converge, how to handle two variable numerical integration

Your main problem consists in the behavior if NIntegrate. Consider: Clear[f]; f[x_] := NIntegrate[t, {t, x, 10}] NIntegrate[f[z], {z, 0, 1 }] This gives error ...
Daniel Huber's user avatar
  • 50.3k
2 votes

Integro-differential equation with double integral

This problem can be solved with the Euler wavelets collocation method even in v.8 as follows ...
Alex Trounev's user avatar
  • 43.4k
2 votes
Accepted

Using ParametricNDSolve does not work for certain parameters

Here is a more compact approach that obtains w and a simultaneously. ...
bbgodfrey's user avatar
  • 61.3k
1 vote

NIntegrate returns TerminatedEvaluation["RecursionLimit"] when called in another function

Block[{}, test[2]] and Module[{}, test[2]] have the same problem. (With works, but I'd think ...
Goofy's user avatar
  • 2,642
1 vote

How can I fix NIntegrate::inumr warning message?

Consider: GduY0[0] what gives an error message: Now the definition of GduY0 is: ...
Daniel Huber's user avatar
  • 50.3k
1 vote

Numerical integral does not agree with analytic integral

There is a workaround. Let us put J[t_] := Integrate[Exp[-a*Cos[b + x]]*Sin[b + x], {x, 0, t}, Assumptions -> t >= 0 && t <= 2*Pi] Then ...
user64494's user avatar
  • 25.7k
1 vote
Accepted

Animate a FindMinimum with NIntegrate

As a higher-level comment, most programming languages use "functions" as building blocks. You explicitly specify inputs and outputs. Mathematica allows you to use "expressions" ...
Yaroslav Bulatov's user avatar

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