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Re: surface area of pdedemo3
Posted:
Jun 25, 2013 1:19 PM


On 6/25/2013 11:33 AM, Steven Finch wrote: > Here is more detail. If I append the existing Matlab PDE demo with > the commands: > > [ux,uy]=pdegrad(p,t,u); > pi*mean(sqrt(1+ux.^2+uy.^2)) > > a coarse estimate 3.8042 of the surface area is obtained. What steps > can be taken to refine this numerical result? Explicit code would be > helpful to me. Thank you! > > > > "Steven Finch" wrote in message > <kqa2u4$2on$1@newscl01ah.mathworks.com>... >> What is the surface area of the saddle surface in >> http://www.mathworks.com/help/pde/examples/minimalsurfaceproblemontheunitdisk.html >> >> ?
After refining the result as follows, I got an estimate of the area of 3.8251. All I did was apply another round of refinemesh, and I set the rtol to 1e4 instead of 1e3 (I don't know if refining rtolis is important or not). To calculate the area, I added up the areas of the triangles on the surface.
I imagine that it is easier and less errorprone to use Bill Greene's suggestion rather than my specialpurpose triangle summation function.
Alan Weiss MATLAB mathematical toolbox documentation
Alan Weiss MATLAB mathematical toolbox documentation



