PRO dustem_write_mix,dir,st

;stop

IF ptr_valid(st[0]) THEN BEGIN
  comments=(*st[0]).comments
  Ncomments=n_elements(comments)
ENDIF ELSE BEGIN
  Ncomments=0L
ENDELSE
  
Nst=n_elements(st)
  

frmts=[ $
         '(A)', $
         '(A)', $
         '(A)', $
         '(A)', $
         '(A)']

;Start loop over type of grain
FOR i=0L,Nst-1 DO BEGIN
  ;Test if the pointer is pointing to something
  IF ptr_valid(st(i)) THEN BEGIN
    frmts=replicate('(A)',n_elements((*st(i)).fmix))
    ;Get filename
    ffile=(*st(i)).file
    fv=str_sep(ffile,'/')
    file=dir+fv(n_elements(fv)-1)
    ;Open file
    message,'Will write MIX file '+file,/continue
    openw,unit,file,/get_lun
    ;Print comments
    IF Ncomments NE 0 THEN BEGIN
      FOR ii=0,Ncomments-1 DO BEGIN
        printf,unit,comments[ii]
      ENDFOR
    ENDIF
    ;Print FMIX
    ;stop
    FOR k=0L,n_elements((*st(i)).fmix)-1 DO BEGIN
      printf,unit,((*st(i)).fmix)(k),format=frmts[k]
    ENDFOR
    close,unit
    free_lun,unit
  ENDIF ELSE BEGIN
    ;left blank intentionally
  ENDELSE
ENDFOR

END