But
===

Perform the product of a matrix by a vector.

The matrix is a data structure of the matr_asse type: it has real or complex values, symmetric or non-symmetric. The vector is a data structure of the type cham_no. It has real or complex values. We require that matrix and vector both have real values or both have complex values (otherwise use the COMB_MATR_ASSE [:ref:`U4.72.01 <U4.72.01>`] or CREA_CHAMP [:ref:`U4.72.04 <U4.72.04>`] commands first) and that they share the same numbering (see command NUME_DDL [:ref:`U4.61.11 <U4.61.11>`]) and that they share the same numbering (see command []).

Produce a cham_no concept.