;+
;
; @file_comments
; write the bathymetry ASCII file of OPA
;
; @categories
; For OPA
;
; @param ZBAT {in}{required}
; the bathymetry, a 2d array
;
; @param FILENAME {in}{required}{type=string}
; It contains the filename
;
; @history
;  Sebastien Masson (smasson\@lodyc.jussieu.fr)
;                      Sept 30, 2003
;    based on batsav2.pro, written by Maurice Imbard, March 17, 1998
;
; @version
; $Id$
;
;-
;
PRO writebat, zbat, filename
;
  compile_opt idl2, strictarrsubs
;
; basic checks
  IF n_params() NE 2 THEN BEGIN
    ras = report( 'bad number of arguments in the call of writebat')
    return
  ENDIF
  IF size(filename, /type) NE 7 THEN BEGIN
    ras = report( 'the filename should be a string')
    return
  ENDIF
  sbat = size(zbat)
  IF sbat[0] NE 2 THEN BEGIN
    ras = report( 'bathymetry array should be 2d array')
    return
  ENDIF
;
  jpi2 = sbat[1]
  jpj2 = sbat[2]
; parameters def
  ifreq  = 40
  ifin   = jpi2/ifreq+1
  irest  = jpi2-(ifin-1)*ifreq
  zbati  = intarr(ifreq)
  zbati2 = intarr(irest)
  i0     = intarr(ifreq/5)
  i1     = intarr(max([1, irest/5]))
;
  openw, iunit, filename, /get_lun
;;
;; fill the file
;;
  printf, iunit, FORMAT = '(1x," bathy IDL     ",2i8)', jpi2, jpj2
  printf, iunit, FORMAT = '(/)'
  il1 = 0
  FOR jn = 1, ifin-1 DO BEGIN
    printf, iunit, FORMAT = '(/)'
    il2 = min([ jpi2-1, il1+ifreq-1] )
    i0[0] = il1+1
    FOR jj = 1, ifreq/5-1 DO BEGIN
      i0[jj] = i0[jj-1]+5
    END
    printf, iunit, FORMAT = '(3x,13(i3,12x))', i0
    printf, iunit, FORMAT = '(/)'
    il3 = il2-(jn-1)*ifreq
    iformat = string('(', il3+2, 'i3)')
    FOR jj =  jpj2-1, 0, -1  DO BEGIN
      zbati[0:il3] = zbat[il1:il2, jj]
      printf, iunit, FORMAT = iformat, jj+1, zbati
    END
    il1 = il1 + ifreq
  END
  printf, iunit, FORMAT = '(/)'
  il2 = min([ jpi2-1, il1+ifreq-1] )
  i1[0] = il1+1
  FOR jj = 1, irest/5-1 DO BEGIN
    i1[jj] = i1[jj-1]+5
  END
  printf, iunit, FORMAT = '(3x,13(i3,12x))', i1
  printf, iunit, FORMAT = '(/)'
  il3 = il2-(ifin-1)*ifreq
  iformat = string('(', il3+2, 'i3)')
  FOR jj =  jpj2-1, 0, -1  DO BEGIN
    zbati2[0:irest-1] = 0
    zbati2[0:il3] = zbat[il1:il2, jj]
    printf, iunit, FORMAT = iformat, jj+1, zbati2
  END
;;
;; end
;;
  close, iunit
  free_lun, iunit
;
  return
end