Documentation on minmax

Task: minmax
Purpose: Forced write of the minimum and maximum data header values
Categories: map analysis

   MINMAX sets the DATAMIN and DATAMAX items in an image in those rare
   cases that you need it computed from a selected area. Most commonly
   when data have been flagged (e.g. with MATHS or IMFLAG).
   See also PUTHD on how to patch a user supplied value for DATAMIN 
   and/or DATAMAX.
   If the min/max was found to be the same, nothing will be done to
   the dataset.

Key: in
   The input dataset name. No default.

Key: region
   The region of interest over which the min and max are to be computed.
   Full region specifications are supported.
   See the Users Manual for instructions on how to specify this.
   Default: the whole dataset

Key: minmax
   If supplied, this is a fast way to set a new value for the min and
   max as you want them. There is no checking if the values are
   correct, or even if ``min   max''. 
   Default: not used.