28 MYRAMATH_EXPORT std::pair< Matrix<float >, DiagonalMatrix<float > > lanczosN(const Action<float >& A, const CMatrixRange<float >& Q, int N, float tolerance = 1.0e-4, int iterations = 50);
29 MYRAMATH_EXPORT std::pair< Matrix<double>, DiagonalMatrix<double> > lanczosN(const Action<double>& A, const CMatrixRange<double>& Q, int N, double tolerance = 1.0e-8, int iterations = 50);