function [y, delta] = polyval(p,x)
// adattamento function del Matlab
//POLYVAL Evaluate polynomial.
//   Y = POLYVAL(P,X), when P is a vector of length N+1 whose elements
//   are the coefficients of a polynomial, is the value of the
//   polynomial evaluated at X.
//
//       Y = P(1)*X^N + P(2)*X^(N-1) + ... + P(N)*X + P(N+1)
//
//   If X is a matrix or vector, the polynomial is evaluated at all
//   points in X.  
//
//   See also POLYFIT.



[m,n] = size(x);
nc = length(p);


// Use Horner's method for general case where X is an array.
y = zeros(m,n);
if length(p)>0, y(:) = p(1); end
for i=2:nc
    y = x .* y + p(i);
end
endfunction