Type commandUserData('xxx') to convert a user-supplied data file 'xxx.dat' to
AUTO format. The converted file is called 's.dat'. The original
file is left unchanged. AUTO automatically sets the period in
PAR(10). Other parameter values must be set in 'stpnt'. (When
necessary, PAR(10) may also be redefined there.) The
constants-file file 'c.xxx' must be present, as the AUTO-constants
'NTST' and 'NCOL' are used to define the new mesh. For examples
of using the 'userData' command see demos 'lor' and 'pen' (where
it has the old name 'fc').