In the user data structure of each vertex a magnetization vector can be stored
if a `magnetization`

problem is initialized.
The third bit of the control word indicates if the values for the magnetization
vector are valid or not. There are three macros `SET_SOL_OK`

,
`RESET_SOL_OK`

and `SOL_OK`

They work analogously to the corresponding macros for an element's error.
The three components of the magnetization vector are accessible by the macros
`M1`

, `M2`

and `M3`

.

All geometrical and numerical data belonging to one vertex are stored in its data structure. Therefore vertex and node are used equivalently. On the contrary Bey's convection-diffusion problem of does distinguish between nodes and vertices: Geometrical and graphical information is stored in the vertices' data structure whereas numerical data are contained in the nodes' data structure.