function read_Climatology(hMainFig)
% Function to read climatology and store result to tsg structure
%
% Input
% -----
% tsg     ............ structure tsg
% type    ............ String describing climatology (annual,sesonal or
%                      monthly)
%
% Output
% ------
% tsg     ............ updated structure tsg
%
% $Id$

% Get data
% -----------------------
tsg = getappdata( hMainFig, 'tsg_data' );

% get last selected climatology
% -----------------------------
s = get(findobj('Tag', 'TAG_UIMENU_CLIMATO_MAIN'), 'Userdata');

% tsg.levitus.type = 'none' or new select climatology is different, load file
% -------------------------------------------------------------------------
if strcmp( tsg.levitus.type, 'none') || ~strcmp(tsg.levitus.type, s.type)

  % construct the filename and read file
  % ------------------------------------
  file = which(['woa01_' s.type  '_surf.nc']);

  % open netcdf climatology file
  % ----------------------------
  levitus = read_file_woa01(file);

  % test for structure concordance
  % ------------------------------
  if isstruct(levitus)
    
    % ok, save last climato state in tsg.levitus structure
    % ----------------------------------------------------
    tsg.levitus.type = s.type;
    tsg.levitus.data = levitus;
    
  else
    
    % show dialog box with help to get climatology file
    % -------------------------------------------------
    errordlg({'NetCDF climatology file :', file, ...
      'not present in you path',...
      'Check your matlab path or download it from',...
      ['ftp://ftp.ifremer.fr/ifremer/ird/us191/oceano/lib/matlab/woa01_' s.type '_surf.nc']},...
      'NetCDF climatology file access error');

    % init tsg.levitus state
    % ----------------------
    tsg.levitus.data = [];
    tsg.levitus.type = 'none';
    
  end
  
end

% save tsg structure
% ------------------
setappdata( hMainFig, 'tsg_data', tsg );