svmlight.html

统计模式识别工具箱（Statistical Pattern Recognition Toolbox）包含： 1

<br>
<span class=comment>%&nbsp;gets&nbsp;data&nbsp;dimensions</span><br>
[dim,num_data&nbsp;]&nbsp;=&nbsp;size(data);<br>
<br>
<span class=comment>%--------------------------------</span><br>
<span class=keyword>switch</span>&nbsp;options.ker<br>
&nbsp;&nbsp;<span class=label>case</span>&nbsp;<span class=quotes>'linear'</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;ker=<span class=quotes>'-t&nbsp;0'</span>;<br>
&nbsp;&nbsp;<span class=label>case</span>&nbsp;<span class=quotes>'rbf'</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;ker=[<span class=quotes>'-t&nbsp;2&nbsp;-g&nbsp;'</span>&nbsp;num2str(1/(2*options.arg^2))];&nbsp;<br>
&nbsp;&nbsp;<span class=label>case</span>&nbsp;<span class=quotes>'poly'</span>&nbsp;<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class=keyword>if</span>&nbsp;length(options.arg)&nbsp;==&nbsp;1,<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ker=[<span class=quotes>'-t&nbsp;1&nbsp;-r&nbsp;1&nbsp;-s&nbsp;1&nbsp;-d&nbsp;'</span>&nbsp;num2str(options.arg)];&nbsp;&nbsp;<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class=keyword>else</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ker=[<span class=quotes>'-t&nbsp;1&nbsp;-s&nbsp;1&nbsp;-r&nbsp;'</span>&nbsp;num2str(options.arg(2))&nbsp;<span class=quotes>'&nbsp;-d&nbsp;'</span>&nbsp;...<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;num2str(options.arg(1))];&nbsp;&nbsp;<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class=keyword>end</span><br>
<span class=keyword>end</span><br>
command=[<span class=quotes>'svm_learn&nbsp;'</span>&nbsp;...<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=quotes>'-c&nbsp;'</span>&nbsp;num2str(options.C)&nbsp;<span class=quotes>'&nbsp;'</span>...<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ker&nbsp;<span class=quotes>'&nbsp;'</span>&nbsp;...<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=quotes>'-v&nbsp;1&nbsp;'</span>&nbsp;...<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=quotes>'-m&nbsp;40'</span>&nbsp;<span class=quotes>'&nbsp;'</span>&nbsp;...<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=quotes>'-j&nbsp;'</span>&nbsp;num2str(options.j)&nbsp;<span class=quotes>'&nbsp;'</span>...<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=quotes>'-e&nbsp;'</span>&nbsp;num2str(options.eps)&nbsp;<span class=quotes>'&nbsp;'</span>...<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=quotes>'-a&nbsp;'</span>&nbsp;alpha_file&nbsp;<span class=quotes>'&nbsp;'</span>&nbsp;examples_file&nbsp;<span class=quotes>'&nbsp;'</span>&nbsp;model_file&nbsp;<span class=quotes>'&nbsp;&gt;&nbsp;'</span>&nbsp;verb_file];<br>
&nbsp;&nbsp;&nbsp;<br>
<span class=comment>%&nbsp;converts&nbsp;data&nbsp;to&nbsp;SVM^light&nbsp;format</span><br>
xy2svmlight(data,examples_file);<br>
&nbsp;&nbsp;&nbsp;&nbsp;<br>
<span class=comment>%&nbsp;call&nbsp;svm_learn</span><br>
[a,b]=unix(command);&nbsp;&nbsp;&nbsp;<br>
<br>
<span class=comment>%&nbsp;parses&nbsp;model&nbsp;file</span><br>
checkfile(model_file);&nbsp;[lines]=textread(model_file,<span class=quotes>'%s'</span>);<br>
<span class=keyword>for</span>&nbsp;i=1:size(lines,1)<br>
&nbsp;&nbsp;&nbsp;<span class=keyword>if</span>&nbsp;strcmpi(&nbsp;lines(i),&nbsp;<span class=quotes>'threshold'</span>&nbsp;)==1,<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;model.b=-str2num(&nbsp;lines{i-2});<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=jump>break</span>;<br>
&nbsp;&nbsp;&nbsp;<span class=keyword>end</span><br>
<span class=keyword>end</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;<br>
checkfile(alpha_file);&nbsp;model.Alpha=textread(alpha_file,<span class=quotes>'%f'</span>);<br>
model.Alpha=model.Alpha(:);<br>
model.Alpha(find(data.y==2))&nbsp;=&nbsp;-model.Alpha(find(data.y==2));<br>
<br>
checkfile(verb_file);<br>
[lines]=textread(verb_file,<span class=quotes>'%s'</span>,-1,<span class=quotes>'bufsize'</span>,5000000,<span class=quotes>'headerlines'</span>,3);<br>
<span class=keyword>for</span>&nbsp;i=1:size(lines,1)<br>
&nbsp;&nbsp;<span class=keyword>if</span>&nbsp;strcmpi(&nbsp;lines{i},&nbsp;<span class=quotes>'misclassified,'</span>&nbsp;),<br>
&nbsp;&nbsp;&nbsp;&nbsp;model.trnerr=str2num(&nbsp;lines{i-1}(2:<span class=keyword>end</span>));<br>
&nbsp;&nbsp;&nbsp;&nbsp;model.trnerr=model.trnerr/length(model.Alpha);<br>
&nbsp;&nbsp;<span class=keyword>end</span><br>
&nbsp;&nbsp;<span class=keyword>if</span>&nbsp;strcmpi(&nbsp;lines(i),&nbsp;<span class=quotes>'vector:'</span>&nbsp;)&nbsp;&&nbsp;strcmpi(&nbsp;lines(i-1),&nbsp;<span class=quotes>'weight'</span>&nbsp;)==1,<br>
&nbsp;&nbsp;&nbsp;&nbsp;tmp=str2num(&nbsp;lines{i+1}(5:<span class=keyword>end</span>));<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class=keyword>if</span>&nbsp;tmp~=0,&nbsp;model.margin=1/tmp;&nbsp;<span class=keyword>else</span>&nbsp;model.margin=[];&nbsp;<span class=keyword>end</span><br>
&nbsp;&nbsp;<span class=keyword>end</span><br>
&nbsp;&nbsp;<span class=keyword>if</span>&nbsp;strcmpi(&nbsp;lines(i),&nbsp;<span class=quotes>'SV:'</span>&nbsp;)==1,<br>
&nbsp;&nbsp;&nbsp;&nbsp;model.nsv=str2num(&nbsp;lines{i+1});<br>
&nbsp;&nbsp;<span class=keyword>end</span><br>
&nbsp;&nbsp;<span class=keyword>if</span>&nbsp;strcmpi(&nbsp;lines(i),&nbsp;<span class=quotes>'evaluations:'</span>&nbsp;)==1,<br>
&nbsp;&nbsp;&nbsp;&nbsp;model.kercnt=str2num(&nbsp;lines{i+1});<br>
&nbsp;&nbsp;<span class=keyword>end</span><br>
<span class=keyword>end</span><br>
<br>
model.nsv&nbsp;=&nbsp;length(find(model.Alpha~=0));<br>
<br>
inx=find(model.Alpha);<br>
model.sv.X&nbsp;=&nbsp;data.X(:,inx);<br>
model.sv.y&nbsp;=&nbsp;data.y(inx);<br>
model.sv.inx&nbsp;=&nbsp;inx;<br>
model.Alpha&nbsp;=&nbsp;model.Alpha(inx);<br>
model.Alpha(find(model.sv.y==2))&nbsp;=&nbsp;-model.Alpha(find(model.sv.y==2));<br>
<br>
<span class=keyword>if</span>&nbsp;strcmp(&nbsp;options.ker,&nbsp;<span class=quotes>'linear'</span>),<br>
&nbsp;&nbsp;model.W&nbsp;=&nbsp;model.sv.X&nbsp;*&nbsp;model.Alpha;<br>
<span class=keyword>end</span><br>
<br>
model.options&nbsp;=&nbsp;options;<br>
model.fun&nbsp;=&nbsp;<span class=quotes>'svmclass'</span>;<br>
<br>
<span class=comment>%&nbsp;deletes&nbsp;temporary&nbsp;files</span><br>
<span class=keyword>if</span>&nbsp;options.keep_files&nbsp;==&nbsp;0,<br>
&nbsp;&nbsp;delete(examples_file);<br>
&nbsp;&nbsp;delete(model_file);<br>
&nbsp;&nbsp;delete(verb_file);<br>
&nbsp;&nbsp;delete(alpha_file);<br>
<span class=keyword>end</span><br>
<br>
model.cputime=toc;<br>
<br>
<span class=jump>return</span>;<br>
<br>
<br>
<span class=defun_kw>function</span>&nbsp;<span class=defun_name>checkfile</span>(<span class=defun_in>fname</span>)<br>
<span class=comment>%&nbsp;Check&nbsp;if&nbsp;file&nbsp;of&nbsp;given&nbsp;name&nbsp;exists.&nbsp;If&nbsp;not&nbsp;then&nbsp;prints</span><br>
<span class=comment>%&nbsp;error.</span><br>
<span class=comment>%&nbsp;</span><br>
<br>
attempts=0;<br>
found&nbsp;=&nbsp;<span class=stack>exist</span>(fname);<br>
<span class=keyword>while</span>&nbsp;attempts&nbsp;&lt;&nbsp;5&nbsp;&&&nbsp;~found<br>
&nbsp;&nbsp;found&nbsp;=&nbsp;<span class=stack>exist</span>(fname);<br>
&nbsp;&nbsp;attempts&nbsp;=&nbsp;attempts+1;&nbsp;&nbsp;<br>
<span class=keyword>end</span><br>
<br>
<span class=keyword>if</span>&nbsp;found&nbsp;==&nbsp;0,<br>
&nbsp;&nbsp;<span class=error>error</span>(<span class=quotes>'File&nbsp;%s&nbsp;not&nbsp;found.\n'</span>,&nbsp;fname);<br>
<span class=keyword>end</span><br>
<br>
<span class=jump>return</span>;<br>
<br>
<span class=comment>%EOF</span><br>
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