function c3 = poly_multiply ( c1, c2 )

%*****************************************************************************80
%
%% poly_multiply multiplies two polynomials.
%
%  Input:
%
%    real c1(d1+1), c2(d2+1): the polynomial factors.
%
%  Output:
%
%    real c3(d3+1): the polynomial product.
%
  d1 = length ( c1 ) - 1;
  d2 = length ( c2 ) - 1;
  d3 = d1 + d2;
  c3 = zeros ( d3 + 1, 1 );
  
  for i = 0 : d1
    for j = 0 : d2
      c3(i+j+1) = c3(i+j+1) + c1(i+1) * c2(j+1);
    end
  end
  
  return
end   
