function s=gcmfaces(varargin);
%object:    create an empty gcmfaces object
%optional input: cell array containing each face data that
%                will be used to fill the gcmfaces object
%pre-requisite : the grid (global mygrid variable) must have been 
%		 defined using grid_load or grid_load_native
%		 providing the blue print for new gcmfaces objects
%note:      this routine used to have several inputs of various types;
%           now only the first input is used, and only if it is a cell array.

global mygrid;

nFaces=mygrid.nFaces;

if nFaces==1; gridType='ll';
elseif nFaces==4; gridType='llpc';
elseif nFaces==5; gridType='llc';
elseif nFaces==6; gridType='cube';
else; error('wrong gcmfaces definition');
end;

nFacesMax=6;

if nargin>1; fld=varargin{1}; else; fld=[]; end;

if iscell(fld);
   s.nFaces=length(fld);
   s.gridType=gridType;
   for iF=1:s.nFaces;
      eval(['s.f' num2str(iF) '=fld{iF};']);
   end;
   for iF=s.nFaces+1:nFacesMax;
      eval(['s.f' num2str(iF) '=[];']);
   end;
else;
    s.nFaces=nFaces;
    s.gridType=gridType;
    for iF=1:nFacesMax;
        eval(['s.f' num2str(iF) '=[];']);
    end;
end;

s = class(s,'gcmfaces');