One class classification

I came across a good learning resource about one class classification:

In practice, weka provides two ways of doing one-class classification: one is under libsvm package; the other one is named: OneClassClassifier (, which is a meta classifier. In this case, you need to choose a basic classifier to go on.

From an experiment of the data set I collected, I noticed that OneClassClassifier with random forest as basic classifier performs better than one-class classification of SVM.


android two views overlap each other

“setZOrderOnTop” can only be called once before the view is attached to the viewgroup. It cannot be used to change the z level dynamically during the runtime.

If need to alter the z order of two views in a group, “setVisibility” can be called through the UI

runOnUiThread(new Runnable() {
public void run() {

thread to alter the Z order.  for instance, ”

Camera preview failed


Inside SurfaceView Holder, make sure to set the type to SURFACE_TYPE_PUSH_BUFFERS

public void onCreate(Bundle savedInstanceState) {
   // ...
   SurfaceView sur=(SurfaceView)findViewById(;
   SurfaceHolder holder =sur.getHolder();