source: trunk/SRC/Grid/ncdf_meshroms.pro @ 327

;+
;
; @file_comments
; read NetCDF grid file created by ROMS
;
; @categories
; Grid
;
; @examples
; IDL> ncdf_meshroms [,' filename']
;
; @param filename {in}{optional}{default='roms_grd.nc'}{type=scalar string}
;    Name of the meshmask file to read. If this name does not contain any "/"
;    and if iodirectory keyword is not specify, then the common variable
;    iodir will be used to define the mesh file path.
;
; @keyword GLAMBOUNDARY {default=those defined in the file}{type=2 elements vector}
;    Longitude boundaries that should be used to visualize the data.
;      lon2 > lon1
;      lon2 - lon1 le 360
;    By default, the common (cm_4mesh) variable key_shift will be automatically
;    defined according to GLAMBOUNDARY.
;
; @keyword ONEARTH {default=1}{type=scalar: 0 or 1}
;    Force the manual definition of data localization on the earth or not
;       0) if the data are not on the earth
;       1) if the data are on earth (in that case we can for example use
;          the labels 'longitude', 'latitude' in plots).
;    The resulting value will be stored in the common (cm_4mesh) variable key_onearth
;    ONEARTH=0 forces PERIODIC=0, SHIFT=0 and is cancelling GLAMBOUNDARY
;
; @keyword GETDIMENSIONS {default=0}{type=scalar: 0 or 1}
;    Activate this keywords if you only want to know the dimension
;    of the domain stored in the mesh file. This dimension will be
;    defined in jpiglo, jpjglo, jpkglo (cm_4mesh common variables)
;
; @keyword PERIODIC {default=computed by using the first line of glamt}{type=scalar: 0 or 1}
;    Force the manual definition of the grid zonal periodicity.
;    The resulting value will be stored in the common (cm_4mesh) variable key_periodic
;    PERIODIC=0 forces SHIFT=0
;
; @keyword NRHO {default=1}{type=scalar}
;    Specify the number of rho level that contain the data we want to explore.
;    This is mainly useful when using <pro>xxx</pro> to get access to the deeper levers and vertical sections.
;
; @keyword SHIFT {default=computed according to glamboundary}{type=scalar}
;    Force the manual definition of the zonal shift that must be apply to the data.
;    The resulting value will be stored in the common (cm_4mesh) variable key_shift
;    Note that if key_periodic=0 then in any case key_shift=0.
;
; @keyword STRCALLING {type=scalar string}
;    the calling command used to call <pro>computegrid</pro> (this is used by <pro>xxx</pro>)
;
; @keyword STRIDE {default=[1, 1, 1]}{type=3 elements vector}
;    Specify the stride in x, y and z direction. The resulting
;    value will be stored in the common (cm_4mesh) variable key_stride
;
; @keyword _EXTRA
; Used to pass keywords to <pro>isafile</pro>
;
; @uses
; cm_4mesh
; cm_4data
; cm_4cal
;
; @restrictions
; ixminmesh, ixmaxmesh, iyminmesh, iymaxmesh, izminmesh, izmaxmesh must
; be defined before calling <pro>ncdf_meshread</pro>. If some of those values
; are equal to -1 they will be automatically defined
;
; In the original ROMS grid, if F grid has (jpi,jpj) points then T
; grid will have (jpi+1,jpj+1) points, U grid will have (jpi,jpj+1)
; points and V grid will have (jpi+1,jpj) points.
; By default C-grid used in this package needs the same number of
; points for T,U,V and F grid, with a T point at the bottom left
; corner of the grid. We therefore ignore the last column of T and
; V points and the last line of T and U points.
;
; Scale factors are computed using the distance between the points
; (which is not the exact definition for irregular grid).
;
; @history
; Sebastien Masson (smasson\@lodyc.jussieu.fr) September 2006
;
; @version
; $Id$
;
;-
PRO ncdf_meshroms, filename, NRHO=nrho, GLAMBOUNDARY=glamboundary $
                  , ONEARTH=onearth, GETDIMENSIONS=getdimensions $
                  , PERIODIC=periodic, SHIFT=shift, STRIDE=stride $
                  , STRCALLING=strcalling, _EXTRA=ex
;
  compile_opt idl2, strictarrsubs
;
@cm_4mesh
@cm_4data
@cm_4cal
  IF NOT keyword_set(key_forgetold) THEN BEGIN
@updatenew
@updatekwd
  ENDIF
;---------------------------------------------------------
;
  tempsun = systime(1)          ; for key_performance
;-------------------------------------------------------
; find meshfile name and open it!
;-------------------------------------------------------
; def of filename by default
  IF n_params() EQ 0 then filename = 'roms_grd.nc'
  meshname = isafile(file = filename, iodirectory = iodir, _EXTRA = ex)
  meshname = meshname[0]
;
  noticebase = xnotice('Reading file !C '+meshname+'!C ...')
; if the meshmask is on tape archive ... get it back
  IF !version.OS_FAMILY EQ 'unix' THEN spawn, '\file '+meshname+' > /dev/null'
  cdfid = ncdf_open(meshname)
  inq = ncdf_inquire(cdfid)
;------------------------------------------------------------
; dimensions
;------------------------------------------------------------
  ncdf_diminq, cdfid, 'xi_rho', name, jpiglo
  ncdf_diminq, cdfid, 'eta_rho', name, jpjglo
  IF n_elements(nrho) NE 0 THEN jpkglo = long(nrho[0]) $
    ELSE jpkglo = 1L
;
  if keyword_set(getdimensions) then begin
    widget_control, noticebase, bad_id = nothing, /destroy
    ncdf_close,  cdfid
    return
  endif
;-------------------------------------------------------
; check that all i[xyz]min[ax]mesh are well defined
;-------------------------------------------------------
  if n_elements(ixminmesh) EQ 0 THEN ixminmesh = 0
  if n_elements(ixmaxmesh) EQ 0 then ixmaxmesh = jpiglo-1
  if ixminmesh EQ -1 THEN ixminmesh = 0
  IF ixmaxmesh EQ -1 then ixmaxmesh = jpiglo-1
  if n_elements(iyminmesh) EQ 0 THEN iyminmesh = 0
  IF n_elements(iymaxmesh) EQ 0 then iymaxmesh = jpjglo-1
  if iyminmesh EQ -1 THEN iyminmesh = 0
  IF iymaxmesh EQ -1 then iymaxmesh = jpjglo-1
  if n_elements(izminmesh) EQ 0 THEN izminmesh = 0
  IF n_elements(izmaxmesh) EQ 0 then izmaxmesh = jpkglo-1
  if izminmesh EQ -1 THEN izminmesh = 0
  IF izmaxmesh EQ -1 then izmaxmesh = jpkglo-1
; definition of jpi,jpj,jpj
  jpi = long(ixmaxmesh-ixminmesh+1)
  jpj = long(iymaxmesh-iyminmesh+1)
  jpk = long(izmaxmesh-izminmesh+1)
;-------------------------------------------------------
; check onearth and its consequences
;-------------------------------------------------------
  IF n_elements(onearth) EQ 0 THEN key_onearth = 1 $
  ELSE key_onearth = keyword_set(onearth)
  IF NOT key_onearth THEN BEGIN
    periodic = 0
    shift = 0
  ENDIF
;-------------------------------------------------------
; automatic definition of key_periodic
;-------------------------------------------------------
  IF n_elements(periodic) EQ 0 THEN BEGIN
    IF jpi GT 1 THEN BEGIN
      ncdf_varget, cdfid, 'lon_rho', xaxis $
                   , offset = [ixminmesh, iyminmesh], count = [jpi, 1]
      xaxis = (xaxis+720) MOD 360
      xaxis = xaxis[sort(xaxis)]
      key_periodic = (xaxis[jpi-1]+2*(xaxis[jpi-1]-xaxis[jpi-2])) $
                     GE (xaxis[0]+360)
    ENDIF ELSE key_periodic = 0
  ENDIF ELSE key_periodic = keyword_set(periodic)
;-------------------------------------------------------
; automatic definition of key_shift
;-------------------------------------------------------
  IF n_elements(shift) EQ 0 THEN BEGIN
    key_shift = long(testvar(var = key_shift))
;  key_shift will be defined according to the first line of glamt.
    if keyword_set(glamboundary) AND jpi GT 1 AND key_periodic EQ 1 $
    THEN BEGIN
      ncdf_varget, cdfid, 'lon_rho', xaxis $
                   , offset = [ixminmesh, iyminmesh], count = [jpi, 1]
; xaxis between glamboundary[0] and glamboundary[1]
      xaxis = xaxis MOD 360
      smaller = where(xaxis LT glamboundary[0])
      if smaller[0] NE -1 then xaxis[smaller] = xaxis[smaller]+360
      bigger = where(xaxis GE glamboundary[1])
      if bigger[0] NE -1 then xaxis[bigger] = xaxis[bigger]-360
;
      key_shift = (where(xaxis EQ min(xaxis)))[0]
      IF key_shift NE 0 THEN BEGIN
        key_shift = jpi-key_shift
        xaxis = shift(xaxis, key_shift)
      ENDIF
;
      IF array_equal(sort(xaxis), lindgen(jpi)) NE 1 THEN BEGIN
        ras = report (['the x axis (1st line of glamt) is not sorted in the increasing order after the automatic definition of key_shift', $
        'please use the keyword shift (and periodic) to suppress the automatic definition of key_shift (and key_periodic) and define by hand a more suitable value...'])
        widget_control, noticebase, bad_id = nothing, /destroy
        return
      ENDIF
;
    ENDIF ELSE key_shift = 0
  ENDIF ELSE key_shift = long(shift)*(key_periodic EQ 1)
;-------------------------------------------------------
; check key_stride and related things
;-------------------------------------------------------
  if n_elements(stride) eq 3 then key_stride = stride
  if n_elements(key_stride) LE 2 then key_stride = [1, 1, 1]
  key_stride = 1l > long(key_stride)
  IF total(key_stride) NE 3  THEN BEGIN
    IF key_shift NE 0 THEN BEGIN
; for explanation, see header of read_ncdf_varget.pro
      jpiright = key_shift
      jpileft = jpi - key_shift - ( (key_stride[0]-1)-((key_shift-1) MOD key_stride[0]) )
      jpi = ((jpiright-1)/key_stride[0]+1) + ((jpileft-1)/key_stride[0]+1)
    ENDIF ELSE jpi = (jpi-1)/key_stride[0]+1
    jpj = (jpj-1)/key_stride[1]+1
    jpk = (jpk-1)/key_stride[2]+1
  ENDIF
;-------------------------------------------------------
; for the variables related to the partial steps
;-------------------------------------------------------
  key_partialstep = 0
  hdept = -1
  hdepw = -1
;-------------------------------------------------------
; default definitions to be able to use read_ncdf_varget
;-------------------------------------------------------
; default definitions to be able to use read_ncdf_varget
  ixmindtasauve = testvar(var = ixmindta)
  iymindtasauve = testvar(var = iymindta)
  izmindtasauve = testvar(var = izmindta)
;
  ixmindta = 0l
  iymindta = 0l
  izmindta = 0l
;
  jpt = 1
  time = 1
  firsttps = 0
;
  firstx = 0
  lastx = jpi-1
  firsty = 0
  lasty = jpj-1
  firstz = 0
  lastz = jpk-1
  nx = jpi
  ny = jpj
  nz = 1
  izminmeshsauve = izminmesh
  izminmesh = 0
;
  key_yreverse = 0
  key_zreverse = 1
  key_gridtype = 'c'
;-------------------------------------------------------
; 2d arrays:
;-------------------------------------------------------
; list the 2d variables that must be read
  namebase  = ['lon_', 'lat_', 'mask_', 'x_', 'y_']
  namebase2 = ['glam', 'gphi', 'mask' , 'd1', 'd2']
;
; read all grid T variables
;
  for i = 0, n_elements(namebase)-1 do begin
    varinq = ncdf_varinq(cdfid, namebase[i]+'rho')
    name = varinq.name
@read_ncdf_varget
    command = namebase2[i]+'t = float(temporary(res))'
    nothing = execute(command)
  ENDFOR
  d1t = 1.e3*(shift(d1t, -1, 0) - d1t)
  d2t = 1.e3*(shift(d2t, 0, -1) - d2t)
  for i = 0, n_elements(namebase2)-1 do begin
    command = namebase2[i]+'t = '+namebase2[i]+'t[0:jpi-2, 0:jpj-2]'
    nothing = execute(command)
  ENDFOR
  tmask = byte(temporary(maskt))
  IF jpk GT 1 THEN tmask = reform(tmask[*]#replicate(1b, jpk), jpi-1, jpj-1, jpk, /overwrite)
  e1u = temporary(d1t)
  e2v = temporary(d2t)
; h: Final bathymetry at RHO-points
    varinq = ncdf_varinq(cdfid, 'h')
    name = varinq.name
@read_ncdf_varget
    hroms = float(temporary(res))
    hroms = hroms[0:jpi-2, 0:jpj-2]
;
; read all grid U variables
;
  jpiglo = jpiglo - 1
  jpi = jpi - 1
  ixmaxmesh = ixmaxmesh - 1
  firstx = 0
  lastx = jpi-1
  nx = jpi
;
  for i = 0, n_elements(namebase)-1 do begin
    varinq = ncdf_varinq(cdfid, namebase[i]+'u')
    name = varinq.name
@read_ncdf_varget
    command = namebase2[i]+'u = float(temporary(res))'
    nothing = execute(command)
  ENDFOR
  tmpsave = 2. * 1.e3 * d1u[0, 0:jpj-2]
  d1u = 1.e3*(shift(d1u, -1, 0) - d1u)
  d2u = 1.e3*(shift(d2u, 0, -1) - d2u)
  for i = 0, n_elements(namebase2)-1 do begin
    command = namebase2[i]+'u = '+namebase2[i]+'u[*, 0:jpj-2]'
    nothing = execute(command)
  ENDFOR
  umaskred = byte((temporary(masku))[jpi-1, *])
  IF jpk GT 1 THEN umaskred = reform(umaskred[*]#replicate(1b, jpk), 1, jpj-1, jpk, /overwrite)
  e1t = temporary(d1u)
  e1t = shift(temporary(e1t), 1, 0)
  e1t[0, *] = temporary(tmpsave)
  e2f = temporary(d2u)
;
; read all grid V variables
;
  jpiglo = jpiglo + 1
  jpi = jpi + 1
  ixmaxmesh = ixmaxmesh + 1
  firstx = 0
  lastx = jpi-1
  nx = jpi
  jpjglo = jpjglo - 1
  jpj = jpj - 1
  iymaxmesh = iymaxmesh - 1
  firsty = 0
  lasty = jpj-1
  ny = jpj
;
  for i = 0, n_elements(namebase)-1 do begin
    varinq = ncdf_varinq(cdfid, namebase[i]+'v')
    name = varinq.name
@read_ncdf_varget
    command = namebase2[i]+'v = float(temporary(res))'
    nothing = execute(command)
  ENDFOR
  d1v = 1.e3*(shift(d1v, -1, 0) - d1v)
  tmpsave = 2. * 1.e3 * d2v[0:jpi-2, 0]
  d2v = 1.e3*(shift(d2v, 0, -1) - d2v)
  for i = 0, n_elements(namebase2)-1 do begin
    command = namebase2[i]+'v = '+namebase2[i]+'v[0:jpi-2, *]'
    nothing = execute(command)
  ENDFOR
  vmaskred = byte((temporary(maskv))[*, jpj-1])
  IF jpk GT 1 THEN vmaskred = reform(vmaskred[*]#replicate(1b, jpk), jpi-1, 1, jpk, /overwrite)
  e1f = temporary(d1v)
  e2t = temporary(d2v)
  e2t = shift(temporary(e2t), 0, 1)
  e2t[*, 0] = temporary(tmpsave)
;
; read all grid F variables
;
  jpiglo = jpiglo - 1
  jpi = jpi - 1
  ixmaxmesh = ixmaxmesh - 1
  firstx = 0
  lastx = jpi-1
  nx = jpi
;
  for i = 0, n_elements(namebase)-1 do begin
    varinq = ncdf_varinq(cdfid, namebase[i]+'psi')
    name = varinq.name
@read_ncdf_varget
    command = namebase2[i]+'f = float(temporary(res))'
    nothing = execute(command)
  ENDFOR
  tmpsave1 = 2. * 1.e3 * d1f[0, *]
  d1f = 1.e3*(shift(d1f, -1, 0) - d1f)
  tmpsave2 = 2. * 1.e3 * d2f[*, 0]
  d2f = 1.e3*(shift(d2f, 0, -1) - d2f)
  fmaskredy = byte(maskf[jpi-1, *])
  IF jpk GT 1 THEN fmaskredy = reform(fmaskredy[*]#replicate(1b, jpk), 1, jpj, jpk, /overwrite)
  fmaskredx = byte((temporary(maskf))[*, jpj-1])
  IF jpk GT 1 THEN fmaskredx = reform(fmaskredx[*]#replicate(1b, jpk), jpi, 1, jpk, /overwrite)
  e1v = temporary(d1f)
  e1v = shift(temporary(e1v), 1, 0)
  e1v[0, *] = temporary(tmpsave1)
  e2u = temporary(d2f)
  e2u = shift(temporary(e2u), 0, 1)
  e2u[*, 0] = temporary(tmpsave2)
;-------------------------------------------------------
; in the case of key_stride ne [1, 1, 1] redefine f points
; coordinates: they must be in the middle of 3 T points
;-------------------------------------------------------
  if key_stride[0] NE 1 OR key_stride[1] NE 1 then BEGIN
; we must recompute glamf and gphif...
    IF jpi GT 1 THEN BEGIN
      if (keyword_set(key_onearth) AND keyword_set(xnotsorted)) $
        OR (keyword_set(key_periodic) AND key_irregular) then BEGIN
        stepxf = (glamt + 720) MOD 360
        stepxf = shift(stepxf, -1, -1) - stepxf
        stepxf = [ [[stepxf]], [[stepxf + 360]], [[stepxf - 360]] ]
        stepxf = min(abs(stepxf), dimension = 3)
        IF NOT keyword_set(key_periodic) THEN $
          stepxf[jpi-1, *] = stepxf[jpi-2, *]
      ENDIF ELSE BEGIN
        stepxf = shift(glamt, -1, -1) - glamt
        IF keyword_set(key_periodic) THEN $
          stepxf[jpi-1, *] = 360 + stepxf[jpi-1, *] $
        ELSE stepxf[jpi-1, *] = stepxf[jpi-2, *]
      ENDELSE
      IF jpj GT 1 THEN BEGIN
        stepxf[*, jpj-1] = stepxf[*, jpj-2]
        stepxf[jpi-1, jpj-1] = stepxf[jpi-2, jpj-2]
      ENDIF
      glamf = glamt + 0.5 * stepxf
    ENDIF ELSE glamf = glamt + 0.5
    IF jpj GT 1 THEN BEGIN
; we must compute stepyf: y distance between T(i,j) T(i+1,j+1)
      stepyf = shift(gphit, -1, -1) - gphit
      stepyf[*, jpj-1] = stepyf[*, jpj-2]
      IF jpi GT 1 THEN BEGIN
        if NOT keyword_set(key_periodic) THEN $
          stepyf[jpi-1, *] = stepyf[jpi-2, *]
        stepyf[jpi-1, jpj-1] = stepyf[jpi-2, jpj-2]
      ENDIF
      gphif = gphit + 0.5 * stepyf
    ENDIF ELSE gphif = gphit + 0.5
  ENDIF
;-------------------------------------------------------
; 1d arrays
;-------------------------------------------------------
  gdept = findgen(jpk)
  gdepw = findgen(jpk)
  e3t = replicate(1., jpk)
  e3w = replicate(1., jpk)
;-------------------------------------------------------
  ncdf_close, cdfid
;-------------------------------------------------------
; Apply Glamboudary
;-------------------------------------------------------
  if keyword_set(glamboundary) AND key_onearth then BEGIN
    if glamboundary[0] NE glamboundary[1] then BEGIN
      glamt = temporary(glamt) MOD 360
      smaller = where(glamt LT glamboundary[0])
      if smaller[0] NE -1 then glamt[smaller] = glamt[smaller]+360
      bigger = where(glamt GE glamboundary[1])
      if bigger[0] NE -1 then glamt[bigger] = glamt[bigger]-360
      glamu = temporary(glamu) MOD 360
      smaller = where(glamu LT glamboundary[0])
      if smaller[0] NE -1 then glamu[smaller] = glamu[smaller]+360
      bigger = where(glamu GE glamboundary[1])
      if bigger[0] NE -1 then glamu[bigger] = glamu[bigger]-360
      glamv = temporary(glamv) MOD 360
      smaller = where(glamv LT glamboundary[0])
      if smaller[0] NE -1 then glamv[smaller] = glamv[smaller]+360
      bigger = where(glamv GE glamboundary[1])
      if bigger[0] NE -1 then glamv[bigger] = glamv[bigger]-360
      glamf = temporary(glamf) MOD 360
      smaller = where(glamf LT glamboundary[0])
      if smaller[0] NE -1 then glamf[smaller] = glamf[smaller]+360
      bigger = where(glamf GE glamboundary[1])
      if bigger[0] NE -1 then glamf[bigger] = glamf[bigger]-360
      toosmall = where(glamu EQ glamboundary[0])
      IF toosmall[0] NE -1 THEN glamu[toosmall] = glamu[toosmall] + 360
      toosmall = where(glamf EQ glamboundary[0])
      IF toosmall[0] NE -1 THEN glamf[toosmall] = glamf[toosmall] + 360
    endif
  endif
;-------------------------------------------------------
; make sure we do have 2d arrays when jpj eq 1
;-------------------------------------------------------
  IF jpj EQ 1 THEN BEGIN
    glamt = reform(glamt, jpi, jpj, /over)
    gphit = reform(gphit, jpi, jpj, /over)
    e1t = reform(e1t, jpi, jpj, /over)
    e2t = reform(e2t, jpi, jpj, /over)
    glamu = reform(glamu, jpi, jpj, /over)
    gphiu = reform(gphiu, jpi, jpj, /over)
    e1u = reform(e1u, jpi, jpj, /over)
    e2u = reform(e2u, jpi, jpj, /over)
    glamv = reform(glamv, jpi, jpj, /over)
    gphiv = reform(gphiv, jpi, jpj, /over)
    e1v = reform(e1v, jpi, jpj, /over)
    e2v = reform(e2v, jpi, jpj, /over)
    glamf = reform(glamf, jpi, jpj, /over)
    gphif = reform(gphif, jpi, jpj, /over)
    e1f = reform(e1f, jpi, jpj, /over)
    e2f = reform(e2f, jpi, jpj, /over)
  ENDIF
;-------------------------------------------------------
  ixmindta = ixmindtasauve
  iymindta = iymindtasauve
  izmindta = izmindtasauve
;-------------------------------------------------------
  widget_control, noticebase, bad_id = nothing, /destroy
;
;====================================================
; grid parameters used by xxx
;====================================================
;
  IF NOT keyword_set(strcalling) THEN BEGIN
    IF n_elements(ccmeshparameters) EQ 0 THEN strcalling = 'ncdf_meshroms' $
    ELSE strcalling = ccmeshparameters.filename
  ENDIF
  IF n_elements(glamt) GE 2 THEN BEGIN
    glaminfo = moment(glamt)
    IF finite(glaminfo[2]) EQ 0 THEN glaminfo = glaminfo[0:1]
    gphiinfo = moment(gphit)
    IF finite(gphiinfo[2]) EQ 0 THEN gphiinfo = gphiinfo[0:1]
  ENDIF ELSE BEGIN
    glaminfo = glamt
    gphiinfo = gphit
  ENDELSE
  romszinfos = {h:hroms, zeta:replicate(0., jpi, jpj), theta_s:-1, theta_b:-1, hc:-1}
  ccmeshparameters = {filename:strcalling  $
          , glaminfo:float(string(glaminfo, format = '(E11.4)')) $
          , gphiinfo:float(string(gphiinfo, format = '(E11.4)')) $
          , jpiglo:jpiglo, jpjglo:jpjglo, jpkglo:jpkglo $
          , jpi:jpi, jpj:jpj, jpk:jpk $
          , ixminmesh:ixminmesh, ixmaxmesh:ixmaxmesh $
          , iyminmesh:iyminmesh, iymaxmesh:iymaxmesh $
          , izminmesh:izminmesh, izmaxmesh:izmaxmesh $
          , key_shift:key_shift, key_periodic:key_periodic $
          , key_stride:key_stride, key_gridtype:key_gridtype $
          , key_yreverse:key_yreverse, key_zreverse:key_zreverse $
          , key_partialstep:key_partialstep, key_onearth:key_onearth}
;
  if keyword_set(key_performance) THEN $
    print, 'time ncdf_meshread', systime(1)-tempsun

;-------------------------------------------------------
   @updateold
;-------------------------------------------------------
   return
 end