% -*- texinfo -*-
% @deftypefn {Function File} {} qtransv (@var{v}, @var{q})
% Transform the 3-D vector @var{v} by the unit quaternion @var{q}.
% Return a column vector.
%
% @example
% vi = (2*real(q)^2 - 1)*vb + 2*imag(q)*(imag(q)'*vb)
% + 2*real(q)*cross(imag(q),vb)
% @end example
%
% @noindent
% Where imag(q) is a column vector of length 3.
% @end deftypefn