title: Tuning svm with libsvm
body: <p>I am new to using the LIBSVM package. I am aware that tuning of parameters is important but I have a few questions.</p>
  
  <p>How to choose the correct kernel? I know linear is fastest, but when should we use another one? Only if the accuracy is too low or is there some other way to program automatic selection of the correct kernel?</p>
  
  <p>Secondly, is there an efficient way to tune SVM in matlab? Only thing I can think of is to make nested <code>for</code>-loops for each parameter I want to test, then train and predict with a classifier. That's a lot of code for something so basic ...</p>