  The surface structure of the magnetic field in stars is one part of the
information about the surface inhomogeneities like brightness, movement or
chemical composition, which is contained in the integral radiation flux but
distorted beyond recognition by losses of information on the topographical
arrangement over the surface because of convolution processes and partial
invisibility.
  Therefore, the complicated processes, beginning with the representation of
the map of the surface field distribution and ending with the resulting
phase-curves of the integral magnetic field, are simulated by a computer
programme. We use this programme as a tool for the analysis of the magnetic
field structure out of the really observed data in phase diagrams by variation
of the parameters and by fitting the calculated curves to the observed ones.
