Description

   The DCX$ANALYZE_DATA routine performs statistical analysis on
   a single data record. This routine is called once for each data
   record to be analyzed.

   During analysis, the DCX facility gathers information that
   DCX$MAKE_MAP uses to create the compression/expansion function
   for the file. After the data records have been analyzed, call
   the DCX$MAKE_MAP routine. Upon receiving the DCX$_AGAIN status
   code from DCX$MAKE_MAP, you must again analyze the same data
   records (in the same order) using DCX$ANALYZE_DATA and then call
   DCX$MAKE_MAP again. On the second iteration, DCX$MAKE_MAP returns
   the DCX$_NORMAL status code, and the data analysis is complete.