Notes for use
=======================

The operator creates an interspectrum concept that makes up the interspectral matrix. Since this matrix is Hermitian and is positively defined, the functions are of the real type for the diagonal terms and of the complex type for the extra-diagonal terms. Only the upper triangular part of the matrix is stored.

These functions can be extracted using the RECU_FONCTION [:external:ref:`U4.32.03 <U4.32.03>`] operator.