eigen: How to get the max number from the upper matrix of the MatrixfXf?

I tried to use

auto temp_matrix_upper = temp_matrix1.triangularView<Upper>(); auto opt_maxium_error = temp_matrix_upper.maxCoeff();

but I got a

‘class Eigen::TriangularView, 2>’ has no member named ‘minCoeff’; did you mean ‘coeff’?