Linked Questions

32 votes
1 answer
4k views

How does Return work?

It is not completely clear to me how Return[] works. The documentation says: Return[expr] returns the value expr from a ...
Szabolcs's user avatar
  • 235k
12 votes
3 answers
1k views

Reduce ODE into 1st order

I have an explicit set of differential equations: $ \ddot{x}=f(x,\dot{x})$ I would like to reduce it in the following way: $ \dot{y} = g(y)$ by substitutions as shown here: wikipedia. I have done ...
Mirko Aveta's user avatar
  • 2,192
14 votes
3 answers
2k views

Solving an integro-differential equation with Mathematica

I try to solve a nonlinear integro-differential equation with this code. Here i used a periodic condition. ...
user55777's user avatar
  • 671
5 votes
1 answer
974 views

PDE of real-world system, integral boundary condition

I've stripped all the physical-significance for clarity, but I know that u[x,t] will be everywhere positive and continuous. here are the equations in Mathematica code: ...
Paul_A's user avatar
  • 487
3 votes
2 answers
594 views

NDSolve:Coupled PDE's, initial-boundary value problem: unreasonable "insufficient number of boundary conditions" error

I tried to NDSolve the PDE system: $$\partial_t y = x\partial_z w \quad\quad \partial_t w = \partial_z y \quad \quad \partial_z x=w $$ for $$(t,z)\in[0,1]\times[-1,0]$$ with initial conditions $$x(...
user avatar
1 vote
1 answer
194 views

Numerically solve of a system of PDEs

I am studying the vibrations of a beam which is coupled to piezoelectric strips. This system is described by the following system of DEs: ...
Eduardo's user avatar
  • 13
0 votes
0 answers
392 views

How to solve Partial differential equation (PDE) with delay!

I just have one question please, I searched on Mathematica documents concerning partial differential equations with delay, all I had found is ordinary differential equations(EDO), that's means ...
walid fssm's user avatar
3 votes
1 answer
160 views

Integral in NDSolve, boundary conditions and initial conditions can't both satisfied

I have serval reaction-diffusion equations to be solved. Which are equivalent to the following problem: First is a simple diffusion equation of $Z(t,r)$ like below: $$ \dfrac{\partial Z}{\partial t}=A(...
Yan QH's user avatar
  • 43
1 vote
1 answer
162 views

System of PDE with integration conditions interior of domain

I am trying to solve this system of pde numerically. I am unable to find any method in Mathematica that can handle this problem. The issue is having this integration condition in the domain. I tried ...
mathfun's user avatar
  • 103
0 votes
0 answers
100 views

Numerical solution of integro-differential equation where the integral term contains a double integral

I have the following code: ...
Pablo Escobar's user avatar
1 vote
0 answers
84 views

NDSolve to solve 2D space 1D time partial integro-differential equations

I have a set of pdes in 2D space and 1D time, one of them is related to the integral in space by Reynolds function. The equations are similar to $$\frac{\partial \phi}{\partial t}=-\frac{\partial \...
Yan QH's user avatar
  • 43