    LOG-APPEND:  Append records from one log file to the end of another.

    Log-append takes certain records from one log file and appends them to
    the end of another log file (which must already exist).  This is
    useful for initializing iterative programs using the state from a
    previous run.  It is also dangerous, however, as no check is made for
    whether the records appended make sense in the new context.

    Usage:

       log-append [ -ignoredtype...] logfile-in [ range ] logfile-out [ index ]

    The records with indexes in the indicated range are read from
    logfile-in and appended to the end of logfile-out, except that records
    with the types given in the optional first argument are ignored.  (See
    log-types.doc for a listing of conventionally-used record types.)  The
    range has the usual form of [low][:[high]][%modulus], as described in
    parse_range in misc.c.  If high and the colon are omitted, high
    defaults to low.  If high is omitted but the colon is present, the
    range extends to the end of the file.  If no range is specified, it
    defaults to the last index for which any records are stored.  Records
    with negative indexes are never copied.

    The records copied are appended to logfile-out, with consecutive
    indexes.  If no final argument is given, these indexes start after the
    index of the last existing record; if the final argument is "-", they
    start at the index of the last existing record.  In either case, the
    indexes start at 0 if only records with negative indexes are present.
    If a number is given as the final index argument, the indexes of
    records start at that number, which must be no smaller than the index
    of the last existing record in the file.

    In the most typical usage, logfile-out contains only specifications,
    with indexes of -1, and the range to copy consists of a single index.
    In this case, the records appended will have index 0, which is
    suitable for initialization of an iterative program.

                Copyright (c) 1995-2003 by Radford M. Neal