; NAME: read_grid2
;   
; PURPOSE: reads ".grid2" output file with MHD grid   
;
; Inputs:
;   file - path to grid2 file
;
; Outputs:
;   x, y, z - MHD coordinates of cell centers
;
; Notes:
;   MHD x,y,z = GSE -x,-y,z
;
; Author:
;   W. Douglas Cramer
;
pro read_grid2, file, x, y, z

  openr,fileid,file,/get_lun
  
  num_x=0
  num_y=0
  num_z=0
  tmp=0.0d

  readf,fileid,num_x
  x=dblarr(num_x)
  ; readf,fileid,x  ;read x correctly, but didnt move file pointer (gdl issue?)
  for i=0,num_x-1 do begin
    readf,fileid,tmp
    x[i]=tmp
  endfor

  readf,fileid,num_y
  y=dblarr(num_y)
  ;readf,fileid,y
  for i=0,num_y-1 do begin
    readf,fileid,tmp
    y[i]=tmp
  endfor

  readf,fileid,num_z
  z=dblarr(num_z)
  ;readf,fileid,z
  for i=0,num_z-1 do begin
    readf,fileid,tmp
    z[i]=tmp
  endfor

  close,fileid
  free_lun,fileid
end