function p = pfit( x, y, poly_order )
% PFIT Polynomial fitter
% Generates coefficients for polynomial fitting of a dataset,
% using a polynomial of order poly_order.
% J. Watlington, 11/18/95

[m,num_samples] = size( x );
poly_order = poly_order + 1;   % num terms is poly_order + 1

% Define the vandermonde matrix for poly_order terms

V = ones( [ num_samples, poly_order ] );    %  preallocate
for loc = 1:num_samples
	prod = 1;
	% first term is already set to one
	for power = 2:poly_order
		prod = prod * x( loc );
		V( loc, power ) = prod;
	end
end
%  Solve for the pseudo-inverse, and multiply it times the input
%  to obtain the optimal solution.
p = (pinv( V ) * y')';