1. Generalities

An interspectral matrix is a Hermitian matrix. The sd_intersection data structure contains the components of this interspectral matrix. Each term in this matrix is a frequency-dependent function. In this data structure, the temporal functions produced by GENE_FONC_ALEA are also stored.

Each term in the matrix is located either by an order number or by the pair (node, component). You can only store the diagonal terms or the upper triangular part of the matrix. The diagonal terms in the matrix are pure real numbers and the extradiagonal terms are complexes.

This data structure is used by the following operators: CALC_INTE_SPEC, DYNA_ALEA_MODAL, PROJ_SPEC_BASE,,,, REST_SPEC_PHYS,, DEFI_SPEC_TURB,,, DYNA_SPEC_MODAL, GENE_FONC_ALEA, POST_DYNA_ALEA, CALC_ESSAI, CALC_SPEC, and DEFI_INTE_SPEC DYNA_ISS_VARI LIRE_INTE_SPEC.