https://svn.lrde.epita.fr/svn/oln/trunk/milena Index: ChangeLog from Ugo Jardonnet &lt;jardonnet(a)lrde.epita.fr&gt; Fix algebra::about_equal. if abs(a-b) < mln_epsilon(T), a and b are about_equal. becomes if abs(a-b) <= mln_epsilon(T), a and b are about_equal. In particular, this update fix the following bug: quat q; q.set_unit(); assert(q.is_unit()) could fail even if q != 0; set_unit() now has is_unit() as postcondition. I realize that it has to be fix also since q could be equal 0; * mln/algebra/quat.hh: . quat.hh | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) Index: mln/algebra/quat.hh --- mln/algebra/quat.hh (revision 1964) +++ mln/algebra/quat.hh (working copy) @@ -410,6 +410,9 @@ quat& quat::set_unit() { v_.normalize(); + + assert(this->is_unit()); + return *this; } @@ -554,10 +557,7 @@ inline bool about_equal(const T& f, const T& q) { - // FIXME: Use abs! - if (f > q) - return (f - q ) < mln_epsilon(T); - return (q - f) < mln_epsilon(T); + return math::abs(q - f) <= mln_epsilon(T); } inline