options sequential && doc

[Dot Deb]

        I have problems reading a file in grads.

        The file is a (time) sequence of blocks of
        (nlon,nlat,nlev,nvar) real. Each block is written with a unique
        write command. So I have an end-of-record for each block.

        The specifications I found in the doc page
        http://iges.org/grads/gadoc/aboutgriddeddata.html do not clarify
        how "OPTIONS sequential" works.

        In particular, it is not clear whether it assumes an
        end-of-record for each (nlon,nlat,nlev) or
        (nlon,nlat,nlev,nvar) block.

        In any case, I' could not read my file properly.

        By the way, in the ctl example reported in the same doc page for
        an unformatted/sequential file there isn't any "sequential"
        option. Why?

        Here is my ctl:
DSET  ^xxx
TITLE xxx

OPTIONS sequential

XDEF    110 LINEAR -22.0  0.4
YDEF    95 LINEAR -19.0  0.4
ZDEF    16 LINEAR 1 1
TDEF    73 LINEAR 00Z04FEB2008 1hr

UNDEF -9.99E33

VARS 35
  HNO3  16      99 HNO3
  HONO  16      99 HONO
  HNO4  16      99 HNO4
[...]