;+
;
; @file_comments
; compute the 3D e3w from e3w and e3w_ps
;
; @categories
; diagnostics
;
; @keyword e1 {default=0}{type=scalar: 0 or 1}
; activate to compute e1t * e3w instead of e3w
; note that of both keywords e1 and e2 are activated we compute e1t * e2t * e3w instead of e3w
;
; @keyword e2 {default=0}{type=scalar: 0 or 1}
; activate to compute e2t * e3w instead of e3w
; note that of both keywords e1 and e2 are activated we compute e1t * e2t * e3w instead of e3w
;
; @returns
; e3w
;
; @uses
; cm_4mesh.pro
;
; @history
; Sebastien Masson, Jan 2011
;
; @version
; $Id$
;
;-
function e3w_3d, e1 = e1, e2 = e2
;
  compile_opt idl2, strictarrsubs
;
@cm_4mesh
;
  CASE 1 OF
    keyword_set(e1) AND keyword_set(e2):arr2d = e1t[firstxt:lastxt, firstyt:lastyt] $
                                              * e2t[firstxt:lastxt, firstyt:lastyt]
    keyword_set(e1):arr2d = e1t[firstxt:lastxt, firstyt:lastyt]
    keyword_set(e2):arr2d = e2t[firstxt:lastxt, firstyt:lastyt]
    ELSE:arr2d = replicate(1.d, nxt*nyt)
  ENDCASE
  e3w_3d = arr2d[*] # e3w[firstzw:lastzw]
  e3w_3d = reform(e3w_3d, nxt, nyt, nzw, /overwrite)    
;
  IF keyword_set(key_partialstep) THEN BEGIN
; Change bottom values with e3t_ps
; level of the bottom of the ocean
    bottom = total(tmask[firstxt:lastxt, firstyt:lastyt, *], 3)
    sea = where(bottom NE 0)
    bottom2 = long(temporary(bottom)) - firstzw
    bottom  = bottom2 - 1L
    ok  = inter(sea, where(bottom  GE 0 AND bottom  LT nzw))
    ok2 = inter(sea, where(bottom2 GE 0 AND bottom2 LT nzw))
; apply e3w_ps to e3w_3D at the bottom of the ocean
    IF ok[0]  NE -1 THEN BEGIN
; the bottom of the ocean in 3D index is:
      bottom  = (lindgen(nxt*nyt))[ok ] + nxt*nyt*(temporary(bottom ))[ok ]
      e3w_3d[bottom ] = arr2d[ok ] * (e3w_ps[firstxt:lastxt, firstyt:lastyt])[ok ]
    ENDIF
    IF ok2[0] NE -1 THEN BEGIN
      bottom2 = (lindgen(nxt*nyt))[ok2] + nxt*nyt*(temporary(bottom2))[ok2]
      e3w_3d[bottom2] = arr2d[ok2] * (e3t_ps[firstxt:lastxt, firstyt:lastyt])[ok2] ; use e3t_ps and not e3w_ps
    ENDIF
  ENDIF
; 
  return, e3w_3d
END