參考
http://eigen.tuxfamily.org/dox/classEigen_1_1Matrix.html
1.Matrix 矩陣
矩陣類多用於單列vector和單行的vector，多用於密集型矩陣或者vectors容器。Vector是隻有一列的矩陣，row-vector是隻有一行的矩陣。可以定義爲固定大小或者動態大小。
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
class Eigen::Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >
The matrix class, also used for vectors and row-vectors.
The Matrix class is the work-horse for all dense (note) matrices and vectors within Eigen. Vectors are matrices with one column, and row-vectors are matrices with one row.
The Matrix class encompasses both fixed-size and dynamic-size objects (note).
The first three template parameters are required:（類型，行、列）
Template Parameters
| _Scalar@anchor | matrix_tparam_scalar Numeric type, e.g. float, double, int or std::complex<float>. User defined sclar types are supported as well (see here). |
| _Rows | Number of rows, or Dynamic |
| _Cols | Number of columns, or Dynamic |
2.定義類型
Typedefs |
|
| typedef Matrix< std::complex < double >, 2, 2 > |
Matrix2cd |
| typedef Matrix< std::complex < float >, 2, 2 > |
Matrix2cf |
| typedef Matrix< double, 2, 2 > | Matrix2d |
| typedef Matrix< float, 2, 2 > | Matrix2f |
| typedef Matrix< int, 2, 2 > | Matrix2i |
| typedef Matrix< std::complex < double >, 2, Dynamic > |
Matrix2Xcd |
| typedef Matrix< std::complex < float >, 2, Dynamic > |
Matrix2Xcf |
| typedef Matrix< double, 2, Dynamic > |
Matrix2Xd |
| typedef Matrix< float, 2, Dynamic > | Matrix2Xf |
| typedef Matrix< int, 2, Dynamic > | Matrix2Xi |
| typedef Matrix< std::complex < double >, 3, 3 > |
Matrix3cd |
| typedef Matrix< std::complex < float >, 3, 3 > |
Matrix3cf |
| typedef Matrix< double, 3, 3 > | Matrix3d |
| typedef Matrix< float, 3, 3 > | Matrix3f |
| typedef Matrix< int, 3, 3 > | Matrix3i |
| typedef Matrix< std::complex < double >, 3, Dynamic > |
Matrix3Xcd |
| typedef Matrix< std::complex < float >, 3, Dynamic > |
Matrix3Xcf |
| typedef Matrix< double, 3, Dynamic > |
Matrix3Xd |
| typedef Matrix< float, 3, Dynamic > | Matrix3Xf |
| typedef Matrix< int, 3, Dynamic > | Matrix3Xi |
| typedef Matrix< std::complex < double >, 4, 4 > |
Matrix4cd |
| typedef Matrix< std::complex < float >, 4, 4 > |
Matrix4cf |
| typedef Matrix< double, 4, 4 > | Matrix4d |
| typedef Matrix< float, 4, 4 > | Matrix4f |
| typedef Matrix< int, 4, 4 > | Matrix4i |
| typedef Matrix< std::complex < double >, 4, Dynamic > |
Matrix4Xcd |
| typedef Matrix< std::complex < float >, 4, Dynamic > |
Matrix4Xcf |
| typedef Matrix< double, 4, Dynamic > |
Matrix4Xd |
| typedef Matrix< float, 4, Dynamic > | Matrix4Xf |
| typedef Matrix< int, 4, Dynamic > | Matrix4Xi |
| typedef Matrix< std::complex < double >, Dynamic, 2 > |
MatrixX2cd |
| typedef Matrix< std::complex < float >, Dynamic, 2 > |
MatrixX2cf |
| typedef Matrix< double, Dynamic, 2 > |
MatrixX2d |
| typedef Matrix< float, Dynamic, 2 > | MatrixX2f |
| typedef Matrix< int, Dynamic, 2 > | MatrixX2i |
| typedef Matrix< std::complex < double >, Dynamic, 3 > |
MatrixX3cd |
| typedef Matrix< std::complex < float >, Dynamic, 3 > |
MatrixX3cf |
| typedef Matrix< double, Dynamic, 3 > |
MatrixX3d |
| typedef Matrix< float, Dynamic, 3 > | MatrixX3f |
| typedef Matrix< int, Dynamic, 3 > | MatrixX3i |
| typedef Matrix< std::complex < double >, Dynamic, 4 > |
MatrixX4cd |
| typedef Matrix< std::complex < float >, Dynamic, 4 > |
MatrixX4cf |
| typedef Matrix< double, Dynamic, 4 > |
MatrixX4d |
| typedef Matrix< float, Dynamic, 4 > | MatrixX4f |
| typedef Matrix< int, Dynamic, 4 > | MatrixX4i |
| typedef Matrix< std::complex < double >, Dynamic, Dynamic > |
MatrixXcd |
| typedef Matrix< std::complex < float >, Dynamic, Dynamic > |
MatrixXcf |
| typedef Matrix< double, Dynamic, Dynamic > |
MatrixXd |
| typedef Matrix< float, Dynamic, Dynamic > |
MatrixXf |
| typedef Matrix< int, Dynamic, Dynamic > |
MatrixXi |
| typedef Matrix< std::complex < double >, 1, 2 > |
RowVector2cd |
| typedef Matrix< std::complex < float >, 1, 2 > |
RowVector2cf |
| typedef Matrix< double, 1, 2 > | RowVector2d |
| typedef Matrix< float, 1, 2 > | RowVector2f |
| typedef Matrix< int, 1, 2 > | RowVector2i |
| typedef Matrix< std::complex < double >, 1, 3 > |
RowVector3cd |
| typedef Matrix< std::complex < float >, 1, 3 > |
RowVector3cf |
| typedef Matrix< double, 1, 3 > | RowVector3d |
| typedef Matrix< float, 1, 3 > | RowVector3f |
| typedef Matrix< int, 1, 3 > | RowVector3i |
| typedef Matrix< std::complex < double >, 1, 4 > |
RowVector4cd |
| typedef Matrix< std::complex < float >, 1, 4 > |
RowVector4cf |
| typedef Matrix< double, 1, 4 > | RowVector4d |
| typedef Matrix< float, 1, 4 > | RowVector4f |
| typedef Matrix< int, 1, 4 > | RowVector4i |
| typedef Matrix< std::complex < double >, 1, Dynamic > |
RowVectorXcd |
| typedef Matrix< std::complex < float >, 1, Dynamic > |
RowVectorXcf |
| typedef Matrix< double, 1, Dynamic > |
RowVectorXd |
| typedef Matrix< float, 1, Dynamic > | RowVectorXf |
| typedef Matrix< int, 1, Dynamic > | RowVectorXi |
| typedef Matrix< std::complex < double >, 2, 1 > |
Vector2cd |
| typedef Matrix< std::complex < float >, 2, 1 > |
Vector2cf |
| typedef Matrix< double, 2, 1 > | Vector2d |
| typedef Matrix< float, 2, 1 > | Vector2f |
| typedef Matrix< int, 2, 1 > | Vector2i |
| typedef Matrix< std::complex < double >, 3, 1 > |
Vector3cd |
| typedef Matrix< std::complex < float >, 3, 1 > |
Vector3cf |
| typedef Matrix< double, 3, 1 > | Vector3d |
| typedef Matrix< float, 3, 1 > | Vector3f |
| typedef Matrix< int, 3, 1 > | Vector3i |
| typedef Matrix< std::complex < double >, 4, 1 > |
Vector4cd |
| typedef Matrix< std::complex < float >, 4, 1 > |
Vector4cf |
| typedef Matrix< double, 4, 1 > | Vector4d |
| typedef Matrix< float, 4, 1 > | Vector4f |
| typedef Matrix< int, 4, 1 > | Vector4i |
| typedef Matrix< std::complex < double >, Dynamic, 1 > |
VectorXcd |
| typedef Matrix< std::complex < float >, Dynamic, 1 > |
VectorXcf |
| typedef Matrix< double, Dynamic, 1 > |
VectorXd |
| typedef Matrix< float, Dynamic, 1 > | VectorXf |
| typedef Matrix< int, Dynamic, 1 > | VectorXi |