Expression of a non-sequential sub-matrix defined by arbitrary sequences of row and column indices.
Template Parameters
XprType
the type of the expression in which we are taking the intersections of sub-rows and sub-columns
RowIndices
the type of the object defining the sequence of row indices
ColIndices
the type of the object defining the sequence of column indices
This class represents an expression of a sub-matrix (or sub-vector) defined as the intersection of sub-sets of rows and columns, that are themself defined by generic sequences of row indices and column indices . Let be the nested matrix, then the resulting matrix has m rows and n columns, and its entries are given by: .
The RowIndices and ColIndices types must be compatible with the following API:
In typical usages of Eigen, this class should never be used directly. It is the return type of DenseBase::operator()(const RowIndices&, const ColIndices&).