       Re: How to solve coupled ODEs and PDEs(2ode+2pde) with NDSolve

• To: mathgroup at smc.vnet.net
• Subject: [mg82998] Re: How to solve coupled ODEs and PDEs(2ode+2pde) with NDSolve
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Tue, 6 Nov 2007 03:47:00 -0500 (EST)
• Organization: Uni Leipzig
• References: <fgk93u\$p9c\$1@smc.vnet.net>

```Hi,

if you have
NDSolve[
{f'[t] == t,
Derivative[0, 1][u][x, t] == Derivative[2, 0][u][x, t] + f[t],
u[x, 0] == x*(1 - x), u[0, t] == 0, u[1, t] == 0,
f == 1/2}, {u[x, t], f[x, t]}, {x, 0, 1}, {t, 0, 2}]

let simpliy depend f[t] on x too, i.e, f[x,t] and write:

NDSolve[
{Derivative[0, 1][f][x, t] == t,
Derivative[0, 1][u][x, t] == Derivative[2, 0][u][x, t] + f[x, t],
u[x, 0] == x*(1 - x), u[0, t] == 0, u[1, t] == 0,
f[x, 0] == 1/2}, {u[x, t], f[x, t]}, {x, 0, 1}, {t, 0, 2}]

Regards
Jens

Santhosh wrote:
> hi all
> I am relatively new to mathematica. I have 2 odes and 2 pdes. When I tried to
> solve them with NDSolve I got following error.
>
> The length of the derivator operator Derivative in xf'[t] is not same as
> number of arguments.
>
> I know the meaning of error. but in my system xf depends on t only.
> any idea from anyone
>