ric direction identifier for RefDof
       FillMtrx        D-by-R matrix with ones in positions where H is filled

       Prefix          File prefix for Abravibe files
       StartNo         File number for first file in series
       StopNo          File number for last file in series
       FuncType        Optional vector. Only specified FuncType(s) (numeric) are imported

 The series of file names from StartNo to StopNo does not need to be
 complete, only existing files are loaded.

 NOTE! If impact dat