function [sv,model]=readmodel(infile,nfeature)
% Usage: [sv,model]=readmodel(infile,nfeature)
% convert libsvm formatted data file into regular format
% infile: ascii string of input file name
% nfeature: feature space dimension
% nclass: number of classes
%   if nclasses = 0 means it is a model file and the parameters 
%   encodes both classes and the lagrange multiplier alpha_i
% call lineparse.m
% (C) 2001 by Yu Hen Hu
% created: 10/11/2001

fid=fopen(infile,'r');
line=1;
sv=[];  % support vectors
line =fgetl(fid); % gets the first line
readsv=0;

while line~=-1, % if not end of file
   % parse into tokens
   linelen=length(line); % # of ch in line
   % 1. read tokens
   i=1; k=0; clear token; token{1}=[];
   while k < linelen,
      k=k+1;
      if line(k)~=' ',
         token{i}=[token{i} line(k)];
      elseif line(k)==' ',   % if it is a space delimiter
         i=i+1; token{i}=[]; % prepare to read the next token
      end
   end % while k loop
   % for some reason, sometimes we read one extra empty token since
   % the last char of a line is a space. In this case, the empty token 
   % will remove it.
   ltoken=length(token);
   if isempty(token{ltoken}), ltoken=ltoken-1; end
   
   % now do parsing use switch statements
   % define a data structure model
   if readsv==0, % read headers
      switch token{1} % token is an ASCII string
      case 'svm_type',
         model.svm_type = token{2};
      case 'kernel_type', 
         model.kernel_type= token{2};
      case 'degree'
         model.degree=str2num(token{2});
      case 'nr_class',
         model.nclass = str2num(token{2});
      case 'total_sv',
         model.nsv = str2num(token{2});
      case 'rho',
         model.rho = str2num(token{2});
      case 'SV',
         readsv=1; 
      end
   elseif readsv==1, % start reading support vectors
      tmp=str2num(token{1});
      alpha=abs(tmp); label=[[tmp>0] [tmp<0]];
      feature=zeros(1,nfeature);
      for i=2:ltoken,
         idx=[]; findidx=0; ftoken=[]; 
         for k=1:length(token{i}),
            if token{i}(k)==':',
               findidx=1;
            else
               if findidx==0,
                  idx=[idx token{i}(k)],
               elseif findidx==1,
                  ftoken=[ftoken token{i}(k)];
               end
            end
         end % for k
         feature(round(str2num(idx)))=str2num(ftoken);
      end % for i=2:ltoken
      sv=[sv; alpha feature label];
   end
   % read the next line
   line =fgetl(fid); % gets the next line
end
st=fclose('all');