rot_mx rot_mx::cancel() const
{
int g = den();
for(std::size_t i=0;i<9;i++) g = scitbx::math::gcd_int(g, num_[i]);
if (g == 0) return *this;
return rot_mx(num_ / g, den() / g);
}
rot_mx rot_mx::inverse() const
{
int det_den3 = num_.determinant();
if (det_den3 == 0) throw error("Rotation matrix is not invertible.");
return rot_mx(
num_.co_factor_matrix_transposed() * (den_*den_), den_) / det_den3;
}
rot_mx rot_mx::inverse_cancel() const
{
int det_den3 = num_.determinant();
if (det_den3 == 0) throw error("Rotation matrix is not invertible.");
rat d(det_den3, den_);
return rot_mx(num_.co_factor_matrix_transposed() * d.denominator(), 1)
.divide(d.numerator());
}
rot_mx operator/(rot_mx const& lhs, int rhs)
{
sg_mat3 new_num;
for(std::size_t i=0;i<9;i++) {
if (lhs.num_[i] % rhs) throw_unsuitable_rot_mx(__FILE__, __LINE__);
new_num[i] = lhs.num_[i] / rhs;
}
return rot_mx(new_num, lhs.den_);
}
rot_mx rot_mx::divide(int rhs) const
{
sg_mat3 new_num;
if (rhs < 0) {
new_num = -num_;
rhs = -rhs;
}
else {
new_num = num_;
}
return rot_mx(new_num, den_ * rhs).cancel();
}
rot_mx rot_mx::accumulate(int type) const
{
CCTBX_ASSERT(den_ == 1);
int ord = order(type);
if (ord == 1) return *this;
CCTBX_ASSERT(ord != 0);
sg_mat3 result(1);
sg_mat3 a(num_);
result += a;
for(int i=2; i < ord; ++i) {
a = a*num_;
result += a;
}
return rot_mx(result, 1);
}
rot_mx
operator-() const { return rot_mx(-num_, den_); }