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Subject: Re: Plotting 3-D Surface & Surface Fitting
Date: Mon, 4 Aug 2008 01:49:02 +0000 (UTC)
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Hi - How do you generate the equation for z=f(x,y) from a
surface fitting?
I am using gridfit and have surface fitted my data
successfully. But the key purpose of my experiment is to
generate the equation for z as a function of x and y.

Thanks.


"John D'Errico" <woodchips@rochester.rr.com> wrote in
message <fj4h2m$ei8$1@fred.mathworks.com>...
> "Eric " <ErcFrgsn@aol.com> wrote in message 
> <fj46nh$cvl$1@fred.mathworks.com>...
> > Does Matlab have a way to create a surface plot from a set 
> > of 3-dimensional (empirical) data points? The data points 
> > (x,y,z) are from a nonlinear system. Also, does Matlab have 
> > a function(s) that can be used generate an equation from a 
> > 3D surface plot?   
> 
> If the surface can be interpreted as a single
> valued function, z(x,y), then griddata or
> more simply gridfit from the File Exchange
> will help here. 
> 
> If your data represents a closed surface, or
> some general convoluted and non-functional
> manifold, then no, there is no tool currently
> in Matlab or on the file exchange to do this.
> 
> John