% VAR computes the variance of the data in the AO.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DESCRIPTION: VAR computes the variance of the data in the AO.
%
% CALL:        ao_out = var(ao_in);
%              ao_out = var(ao_in, pl);
%
% <a href="matlab:utils.helper.displayMethodInfo('ao', 'var')">Parameters Description</a>
%
% VERSION:     $Id: var.m,v 1.40 2011/04/19 18:48:11 ingo Exp $
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function varargout = var(varargin)
  
  % Check if the method was called by another method
  callerIsMethod = utils.helper.callerIsMethod;
  
  % Settings
  operatorName = 'var';
  dxFcn = [];
  
  if callerIsMethod
    in_names = {};
  else
    % Collect input variable names
    in_names = cell(size(varargin));
    for ii = 1:nargin,in_names{ii} = inputname(ii);end
  end
  
  % Here we are forced to collect objects so that we can check that each ao
  % is the correct type for doing diag.
  as = utils.helper.collect_objects(varargin(:), 'ao', in_names);
  
  % We filter out the data3D objects here since we don't know what to do
  % with them so far.
  aos = [];
  for kk=1:numel(as)
    if isa(as(kk).data, 'data3D')
      warning('!!! Skipping ao [%s] - %s can''t operate on data3D objects at the moment.', as(kk).name, operatorName);
    else
      aos = [aos as(kk)];
    end
  end
  if isempty(aos) % try for getInfo
    out = ao.applymethod(0, callerIsMethod, in_names, operatorName, dxFcn, @getInfo, @getDefaultPlist, varargin{:});
    varargout{1} = out;
    return
  end
  
  
  copyObjects = nargout>0;
  [bs, pl] = ao.applymethod(copyObjects, callerIsMethod, in_names, operatorName, dxFcn, @getInfo, @getDefaultPlist, varargin{:});
  
  bs = fixAxisData(bs, pl);
  
  if isa(bs, 'ao')
    % Clear errors
    bs.clearErrors(pl);
  end
  
  % set outputs
  varargout = utils.helper.setoutputs(nargout, bs);
end

%--------------------------------------------------------------------------
% Get Info Object
%--------------------------------------------------------------------------
function ii = getInfo(varargin)
  ii = minfo.getInfoAxis(mfilename, @getDefaultPlist, varargin);
end

%--------------------------------------------------------------------------
% Get Default Plist
%--------------------------------------------------------------------------

function plout = getDefaultPlist(set)
  persistent pl;
  persistent lastset;
  if ~exist('pl', 'var') || isempty(pl) || ~strcmp(lastset, set)
    pl = buildplist(set);
    lastset = set;
  end
  plout = pl;
end

function plout = buildplist(varargin)
  plout = plist.getDefaultAxisPlist(varargin{:});
end