;--------------------------------------------------------
undef("dim_maxind")
function dim_maxind(x, nDim[1]:integer)
;
; This is a modification of the original algorithmn posted to ncl-talk by
; Dave Allured (NOAA Affilate): April, 2016
;
local dimx, rankx, N, xmax, nmsgx, dim_xmax, t, tr, mask1
begin
  dimx  = dimsizes(x)
  rankx = dimsizes(dimx)

  if (nDim.ne.0) then
      print("dim_maxind: *** Currently nDim must be set to zero; nDim="+nDim)
      return( new(dimx(1:), integer, -99) )
  end if

  if (rankx.gt.4) then
      print("dim_maxind: *** Currently 1D, 2D, 3D, 4D are supported; rank="+rankx)
      print("                This corresponds to the leftmost dimension.")
      return( new(dimx(1:), integer, -99) )
  end if

  if (rankx.eq.1) then
      ind_xmax           = maxind(x)
      ind_xmax@long_name = "index of 1st  max value"
      ind_xmax@tag       = "dim_maxind"
      return(ind_xmax)
  end if

  N     = dimx(nDim)    ; size of the dimension corresponding to 'nDim'    

  xmax     = dim_max_n_Wrap (x, nDim)
  dim_xmax = dimsizes(xmax)
  ind_xmax = new (dim_xmax, integer, -99 )


  if (rankx.eq.2) then
      do t = 1, N
         tr = N-t
         mask1    = (x(tr,:) .ge. xmax)
         mask1    = where (ismissing(mask1), False, mask1)
         ind_xmax = where (mask1, tr, ind_xmax)
      end do
  end if

  if (rankx.eq.3) then
      do t = 1, N
         tr = N-t
         mask1    = (x(tr,:,:) .ge. xmax)
         mask1    = where (ismissing(mask1), False, mask1)
         ind_xmax = where (mask1, tr, ind_xmax)
      end do
  end if

  if (rankx.eq.4) then
      do t = 1, N
         tr = N-t
         mask1    = (x(tr,:,:,:) .ge. xmax)
         mask1    = where (ismissing(mask1), False, mask1)
         ind_xmax = where (mask1, tr, ind_xmax)
      end do
  end if

  copy_VarCoords(xmax, ind_xmax)
  ind_xmax@long_name = "index of 1st  max value"
  ind_xmax@tag       = "dim_maxind"

  return(ind_xmax)
end
;--------------------------------------------------
undef("dim_minind")
function dim_minind(x, nDim[1]:integer)
;
; It is a modification of the original algorithmn posted to ncl-talk  
; Dave Allured (NOAA Affilate): April, 2016
;
local dimx, rankx, N, xmin, dim_xmin, t, tr, mask1
begin
  dimx  = dimsizes(x)
  rankx = dimsizes(dimx)

  if (nDim.ne.0) then
      print("dim_minind: *** Currently nDim must be set to zero; nDim="+nDim)
      return( new(dimx(1:), integer, -99) )
  end if

  if (rankx.gt.4) then
      print("dim_minind: *** Currently 1D, 2D, 3D, 4D are supported; rank="+rankx)
      print("                This corresponds to the leftmost dimension.")
      return( new(dimx(1:), integer, -99) )
  end if

  if (rankx.eq.1) then
      ind_xmin           = minind(x)
      ind_xmin@long_name = "index of 1st min value"
      ind_xmin@tag       = "dim_minind"
      return(ind_xmin)
  end if

  N     = dimx(nDim)    ; size of the dimension corresponding to 'nDim'    

  xmin     = dim_min_n_Wrap (x, nDim)
  dim_xmin = dimsizes(xmin)
  ind_xmin = new (dim_xmin, integer, -99)

  if (rankx.eq.2) then
      do t = 1, N
         tr = N-t
         mask1    = (x(tr,:) .le. xmin)
         mask1    = where (ismissing(mask1), False, mask1)
         ind_xmin = where (mask1, tr, ind_xmin)
      end do
  end if

  if (rankx.eq.3) then
      do t = 1, N
         tr = N-t
         mask1    = (x(tr,:,:) .le. xmin)
         mask1    = where (ismissing(mask1), False, mask1)
         ind_xmin = where (mask1, tr, ind_xmin)
      end do
  end if

  if (rankx.eq.4) then
      do t = 1, N
         tr = N-t
         mask1    = (x(tr,:,:,:) .le. xmin)
         mask1    = where (ismissing(mask1), False, mask1)
         ind_xmin = where (mask1, tr, ind_xmin)
      end do
  end if

  copy_VarCoords(xmin, ind_xmin)
  ind_xmin@long_name = "index of 1st  min value"
  ind_xmin@tag       = "dim_minind"

  return(ind_xmin)
end