1. Generalities

The sd_liste_rela data structure is a « volatile » data structure that serves in operators AFFE_CHAR_XXXX as an intermediate structure between user data (the linear relationships to be dualized) and their translation into Lagrange finite elements (in LIGREL of CHARGE) and in CARTES containing the coefficients of the relationships.

Basically, the idea is as follows: we store the linear relationships gradually (one by one) in an sd_liste_rela (routine AFRELA) then we « pour » the sd_liste_rela into the sd_char_xxx at the end of the command (routine AFLRCH).

Note:

you can create sd_liste_relay within the same command AFFE_CHAR_XXX. You must then « pour » each of these SDs into the.sd_char_xxx. This makes it possible to make the various routines that manage linear relationships independent: * caddli, cafaci, …