title: What does TriScatteredInterp in Matlab do?
body: <p>I am trying to understand the <code>TriScatteredInterp</code> in Matlab.
  I followed sample program in the help file.</p>
  
  <pre><code>x = rand(100,1)*4-2;
  y = rand(100,1)*4-2;
  z = x.*exp(-x.^2-y.^2);   
  Construct the interpolant:
  F = TriScatteredInterp(x,y,z);
  </code></pre>
  
  <p>What I observe is F.X is same as x and y and F.V is same as z;</p>
  
  <pre><code>ti = -2:.25:2;
  [qx,qy] = meshgrid(ti,ti);
  qz = F(qx,qy); 
  </code></pre>
  
  <p>I consider linear interpolation is done in the <code>qz = F(qx,qy);</code>. How does it do for the linear interpolation?
  Thanks</p>