Spline2D or Piecewise Continuous 2D Polynomials

Spline2D is a work in progress. Currently it only matches C0 (continuous function) not C1 (continuous in 1st derivative) or C2 (continuous in 2nd derivative), which will be added later.

Spline2D requires PolyVal2D:
http://www.mathworks.com/matlabcentral/fileexchange/41097-polyval2d-and-polyfit2d

Spline2D is hosted on Github in a Gist here:
https://gist.github.com/mikofski/5503414

%SPLINEFIT2D Fit 2D data to a set of piecewise continuous polynomials.
% PP = SPLINEFIT2D(F,X,Y,N,M,XB,YB) fits F(X,Y) with polynomials of order
% N, M respectively, within the each pair of consecutive bounds [XB(i) XB(i+1)]
% and [YB(i) YB(i + 1)] for i from 1 to NUMEL(XB)-1 and NUMEL(YB)-1, respectively.

%SPLINEVAL2D Evaluate 2D data to a set of piecewise continuous polynomials.
% F = SPLINEFIT2D(PP,X,Y,N,M,XB,YB) evaluates F(X,Y) with polynomials of order
% N, M respectively, within the each pair of consecutive bounds [XB(i) XB(i+1)]
% and [YB(i) YB(i + 1)] for i from 1 to NUMEL(XB)-1 and NUMEL(YB)-1, respectively.