On 8/23/2015 10:36 AM, Alan Ray wrote:Hi, i would like to know how to have a number solution from this elliptic equation:
"Nasser M. Abbasi" wrote in message <mrckbp$1fm$1...@speranza.aioe.org>...There is a bit of a learning curve with PDE Toolbox. I suggest that you
On 8/23/2015 7:12 AM, Alan Ray wrote:How do I use pdenonlin in my pde?
Hi I wish to solve numerically the following boundary condition PDEproblem:
= 0
u_{xx}+u_{yy} = \sqrt{u} + (u_x)^2/u^{3/2}
with BCS: u(0, y) = 1, D[1](u)(1, y) = 0, u(x, 0) = 1, D[2](u)(x, 0)
the above problem,
Is there a routine or script in Matlab which is ready to be used for
or do I need to write my own script, which I am a bit weak inprogramming.
And I don't know of any nonlinear methods that I can use for this PDE. >> >
if you have the pde toolbox you can try
http://www.mathworks.com/help/pde/index.html
http://www.mathworks.com/help/pde/ug/pdenonlin.html
"[u,res] = pdenonlin(model,c,a,f) solves the nonlinear scalar PDE
problem"
I just see that it's used in one case of minimal surfaces, how to use it in my case?
open the PDE app by entering
pdetool
at the command line (I assume that you have a PDE Toolbox license). Then draw your geometry, which I think is a square from (0,0) to (1,1). I
suggest that you use the Snap option.
Then set the boundary conditions by entering Boundary Mode,
double-clicking the edges one at a time, and entering your boundary conditions. For the Dirichlet conditions set h = 1 and r to be the value (the description of the equation is in the dialog box). For the Neumann condition, the default q = 0 and g = 0 will do.
To get a nonlinear solver, from the Solve > Parameters menu, choose the nonlinear solver. You will have to figure out how to input the
coefficients for your problem, too, but that should be straightforward. Hint: c = 1, a = 0, but f contains your nonlinear function. Make sure
you get the sign correct!
The documentation should help.
Good luck,
Alan Weiss
MATLAB mathematical toolbox documentation
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