function SaveCalFile(cal, filespec, dir)
% SaveCalFile(cal, [filespec], [dir])
%
% Saves calibration data in the structure "cal" to a
% calibration file in the CalData folder.
%
% If filespec is not passed, then it saves to default.mat
% in the CalData folder.  If filespec is an integer, saves
% to screenN.mat.  If filespec is a string, saves to string.mat.
% You can also pass the name with the training .mat already there.
%
% Saves to existing file if it is found, otherwise creates a
% new calibration file.
%
% See also LoadCalFile, CalDataFolder.
%
% 5/28/96  dgp  Wrote it.
% 6/6/96   dgp  Use CalibrationsFolder.
% 7/25/96  dgp  Use CalDataFolder.
% 8/4/96   dhb  More flexible filename interface.
% 8/21/97  dhb  Rewrite for cell array convention.
% 8/25/97  dhb, pbe  Fix bug in cell array handling.
% 8/26/97  dhb  Make saving code parallel LoadCalFile.
% 5/18/99  dhb  Add optional directory arg.
% 8/10/00  dhb  Fix loading code for default.mat
% 7/9/02   dhb  Incorporate filespec/filename fix as suggested by Eiji Kimura.
% 3/27/12  dhb  Pass dir to LoadCalFile call, so that it does the right thing
%               in cases where cal file location is expilcitly passed.
% 4/2/13   dhb  Updated for subdir searching logic.
% 4/12/13  dhb  Make this save to cal file folder when file doesn't yet exist.
% 6/2/13   dhb  More robust about whether passed filespec contains the trailing '.mat'.
% 11/30/14 dhb  Handle case where .mat isn't in passed filename, and name is less then 5 chars long.

% Set the filename
if nargin < 2 || isempty(filespec)
	filespec = 'default';
	filename = ['default.mat'];
elseif ischar(filespec)
	if (length(filespec) >= 5)
        if (~strcmp(filespec(end-3:end),'.mat'))
            filename = [filespec '.mat'];
        else
            filename = filespec;
        end
    else
        filename = [filespec '.mat'];
    end
else
	filename = [sprintf('screen%d.mat',filespec)];
end

if nargin < 3 || isempty(dir)
	dir = CalDataFolder(0,filename);
end

% Load the file to get older calibrations
[oldCal, oldCals, fullFilename] = LoadCalFile(filespec, [], dir);
if isempty(oldCals)
	cals = {cal}; %#ok<NASGU>
    eval(['save ' QuoteString(fullFilename) ' cals']);
else
	nOldCals = length(oldCals);
	cals = oldCals;
	cals{nOldCals+1} = cal; %#ok<NASGU>
    eval(['save ' QuoteString(fullFilename) ' cals']);
end