[eigen] Matrix types - please explain!

[Helmut Jarausch <jarausch@xxxxxxxxxxxxxxxxxxx>]

Hi,

looking for the type of expressions like
Mat.block(.....) and Mat.topRightConer(..), etc

I have seen the following types in  test/householder.cpp :

  typedef Matrix<Scalar, MatrixType::RowsAtCompileTime,  
MatrixType::RowsAtCompileTime> SquareMatrixType;
  typedef Matrix<Scalar, MatrixType::ColsAtCompileTime,  
MatrixType::ColsAtCompileTime> RightSquareMatrixType;
  typedef Matrix<Scalar, MatrixType::ColsAtCompileTime,  
MatrixType::RowsAtCompileTime> TMatrixType;

  typedef Matrix<Scalar, Dynamic, MatrixType::ColsAtCompileTime>  
HBlockMatrixType;
  typedef Matrix<Scalar, MatrixType::RowsAtCompileTime, Dynamic>  
VBlockMatrixType;


Can anybody please explain the difference?

What type would the following (C++11) code

MatrixXd Mat;
auto SubMatrix= Mat.block(i,j,rows,cols);

assign to SubMatrix ?

Many thanks for your help,
Helmut.