Re: NDSolve with Boundary Condition
- To: mathgroup at smc.vnet.net
- Subject: [mg107708] Re: [mg107694] NDSolve with Boundary Condition
- From: Patrick Scheibe <pscheibe at trm.uni-leipzig.de>
- Date: Wed, 24 Feb 2010 06:18:53 -0500 (EST)
- References: <201002231303.IAA16128@smc.vnet.net>
Hi, check D[f[x, y], x] // InputForm which gives Derivative[1, 0][f][x, y] Therefore, you can use something like Derivative[1, 0][f][0, y] == blub to give the values at the 0-boundary. If you want a working sample, read the NDSolve documentation carefully. Cheers Patrick On Tue, 2010-02-23 at 08:03 -0500, marjan wrote: > Dear MathGroup members, > > Please help me with this: > I am trying to solve an numerical equation: sol = NDSolve[{D[Y[z, t], > z, z] + > 10^12 Sin[Y[z, t]] Cos[Y[z, t]] == D[Y[z, t], t] > with boundary conditions: d(Y[a, t])/dz = 2*10^6 and d(Y[b, t])/dz > = 2*10^6 , but i don't know how to write the boundary condition in > this equation. when I write it like D[Y[a, t], z] == 20*10^5, D[Y [b, > t], z] == 20*10^5 Mathematica gives this error > > NDSolve::deqn: equation or list of equations expected instead of > "false" in the first argument {D[Y[z, t], z, z] + > 10^12 Sin[Y[z, t]] Cos[Y[z, t]] == D[Y[z, t], t] , False,False} > > Thanks for your attention > Marjan > > >
- References:
- NDSolve with Boundary Condition
- From: marjan <marjan84@gmail.com>
- NDSolve with Boundary Condition