% -*- texinfo -*-
% @deftypefn {Function File} {} fftconv (@var{a}, @var{b}, @var{n})
% Return the convolution of the vectors @var{a} and @var{b}, as a vector
% with length equal to the @code{length (a) + length (b) - 1}. If @var{a}
% and @var{b} are the coefficient vectors of two polynomials, the returned
% value is the coefficient vector of the product polynomial.
%
% The computation uses the FFT by calling the function @code{fftfilt}. If
% the optional argument @var{n} is specified, an N-point FFT is used.
% @end deftypefn