function keep(varargin)

% ------------------------------------------------------------------------
% This function keeps variables specified and deteletes the rest of 
% variables in your workspace.
%
% For example, if you have x, y, and z in your workspace,
% "keep x" clears y and z, and x will remain in the workspace.
% ------------------------------------------------------------------------
% 05/14/06  ver. 1.0
%
% Written by Munechika Katayama 
% ------------------------------------------------------------------------


% -- If there are no input arguments, does nothing --
if isempty(varargin)
    return
end

% -- Find all variables in the caller workspace --
allvar = evalin('caller','who');

% -- Determine variables to be erased --
clearvar = setdiff(allvar, varargin);

% -- Check whether the input variables are in the workspace --
varin = intersect(allvar, varargin);
varout = setdiff(varargin, varin);

if isempty(varout) == 0
    warning('Variable "%s" does not exist in the workspace', char(varout))
end


% -- Create a string of the list of variables --
clearvar = [char(clearvar) char(kron(ones(length(clearvar),1), ' '))];
[clearvar errmsg] = sprintf('%s', clearvar');

% -- Delete the rest of the variables --
evalin('caller',['clear ',clearvar])