Incremental orthogonal polynomial interpolation for 2D.

   [f, esys, eeval, edom] = interporth2inc(x, Fxt, tol, inc, domain)

   f = interporth2inc(x, Fxt) interpolates an expression by using the
   Chebyshev or Legendre points. In this version an incremental scheme is
   applied, and the interpolation degree is automatically found.

Inputs (required)
   x      = independent tau variable (itau object).
   Fxt    = two variable function F(x, t) (char).     

Inputs (optional)
   tol    = tolerance for precicion (double). 
   inc    = step of polynomial degree (integer).
   domain = rectangular domain (double vector: [x1 x2 y1 y2]).

   f      = coeficients of interpolation (double matrix).
   esys   = error in the linear system (double vector).
   eeval  = (max.) error in the evaluation (double scalar).
   edom   = error in the full domain (double matrix).

See also
  interporth, interporthinc and interporth2.