Method diagonalSize

python/include/Eigen/src/Core/MatrixBase.h:100–101

\returns the size of the main diagonal, which is min(rows(),cols()). * \sa rows(), cols(), SizeAtCompileTime. */

    /** \returns the size of the main diagonal, which is min(rows(),cols()).
      * \sa rows(), cols(), SizeAtCompileTime. */
    EIGEN_DEVICE_FUNC
    inline Index diagonalSize() const { return (numext::mini)(rows(),cols()); }

    typedef typename Base::PlainObject PlainObject;