10 #ifndef EIGEN_DETERMINANT_H 11 #define EIGEN_DETERMINANT_H 17 template<
typename Derived>
19 inline const typename Derived::Scalar bruteforce_det3_helper
20 (
const MatrixBase<Derived>& matrix,
int a,
int b,
int c)
22 return matrix.coeff(0,a)
23 * (matrix.coeff(1,b) * matrix.coeff(2,c) - matrix.coeff(1,c) * matrix.coeff(2,b));
26 template<
typename Derived,
27 int DeterminantType = Derived::RowsAtCompileTime
28 >
struct determinant_impl
30 static inline typename traits<Derived>::Scalar run(
const Derived& m)
32 if(Derived::ColsAtCompileTime==
Dynamic && m.rows()==0)
33 return typename traits<Derived>::Scalar(1);
34 return m.partialPivLu().determinant();
38 template<
typename Derived>
struct determinant_impl<Derived, 1>
40 static inline EIGEN_DEVICE_FUNC
41 typename traits<Derived>::Scalar run(
const Derived& m)
47 template<
typename Derived>
struct determinant_impl<Derived, 2>
49 static inline EIGEN_DEVICE_FUNC
50 typename traits<Derived>::Scalar run(
const Derived& m)
52 return m.coeff(0,0) * m.coeff(1,1) - m.coeff(1,0) * m.coeff(0,1);
56 template<
typename Derived>
struct determinant_impl<Derived, 3>
58 static inline EIGEN_DEVICE_FUNC
59 typename traits<Derived>::Scalar run(
const Derived& m)
61 return bruteforce_det3_helper(m,0,1,2)
62 - bruteforce_det3_helper(m,1,0,2)
63 + bruteforce_det3_helper(m,2,0,1);
67 template<
typename Derived>
struct determinant_impl<Derived, 4>
69 typedef typename traits<Derived>::Scalar Scalar;
70 static EIGEN_DEVICE_FUNC
71 Scalar run(
const Derived& m)
73 Scalar d2_01 = det2(m, 0, 1);
74 Scalar d2_02 = det2(m, 0, 2);
75 Scalar d2_03 = det2(m, 0, 3);
76 Scalar d2_12 = det2(m, 1, 2);
77 Scalar d2_13 = det2(m, 1, 3);
78 Scalar d2_23 = det2(m, 2, 3);
79 Scalar d3_0 = det3(m, 1,d2_23, 2,d2_13, 3,d2_12);
80 Scalar d3_1 = det3(m, 0,d2_23, 2,d2_03, 3,d2_02);
81 Scalar d3_2 = det3(m, 0,d2_13, 1,d2_03, 3,d2_01);
82 Scalar d3_3 = det3(m, 0,d2_12, 1,d2_02, 2,d2_01);
83 return internal::pmadd(-m(0,3),d3_0, m(1,3)*d3_1) +
84 internal::pmadd(-m(2,3),d3_2, m(3,3)*d3_3);
87 static EIGEN_DEVICE_FUNC
88 Scalar det2(
const Derived& m,
Index i0,
Index i1)
90 return m(i0,0) * m(i1,1) - m(i1,0) * m(i0,1);
93 static EIGEN_DEVICE_FUNC
94 Scalar det3(
const Derived& m,
Index i0,
const Scalar& d0,
Index i1,
const Scalar& d1,
Index i2,
const Scalar& d2)
96 return internal::pmadd(m(i0,2), d0, internal::pmadd(-m(i1,2), d1, m(i2,2)*d2));
106 template<
typename Derived>
110 eigen_assert(rows() == cols());
111 typedef typename internal::nested_eval<Derived,Base::RowsAtCompileTime>::type Nested;
112 return internal::determinant_impl<typename internal::remove_all<Nested>::type>::run(derived());
117 #endif // EIGEN_DETERMINANT_H Namespace containing all symbols from the Eigen library.
Definition: Core:141
EIGEN_DEFAULT_DENSE_INDEX_TYPE Index
The Index type as used for the API.
Definition: Meta.h:74
Definition: Eigen_Colamd.h:50
const int Dynamic
Definition: Constants.h:22
Scalar determinant() const
Definition: Determinant.h:108