function opt=varargin2struct(varargin)
%
% opt=varargin2struct('param1',value1,'param2',value2,...)
%   or
% opt=varargin2struct(...,optstruct,...)
%
% convert a series of input parameters into a structure
%
% authors:Qianqian Fang (fangq<at> nmr.mgh.harvard.edu)
% date: 2012/12/22
%
% input:
%      'param', value: the input parameters should be pairs of a string and a value
%       optstruct: if a parameter is a struct, the fields will be merged to the output struct
%
% output:
%      opt: a struct where opt.param1=value1, opt.param2=value2 ...
%
% license:
%     BSD, see LICENSE_BSD.txt files for details 
%
% -- this function is part of jsonlab toolbox (http://iso2mesh.sf.net/cgi-bin/index.cgi?jsonlab)
%

len=length(varargin);
opt=struct;
if(len==0) return; end
i=1;
while(i<=len)
    if(isstruct(varargin{i}))
        opt=mergestruct(opt,varargin{i});
    elseif(ischar(varargin{i}) && i<len)
        opt=setfield(opt,varargin{i},varargin{i+1});
        i=i+1;
    else
        error('input must be in the form of ...,''name'',value,... pairs or structs');
    end
    i=i+1;
end