title: Android MotionEvent onTouch jumps even if my finger is still in one point
body: <p>recently i try to use the ontouch event on a view, and i realise that the X axis jumps over 5 or 10 pixels ramdomly even when my finger is still, is a hardware issue? i read that the ontouch move event is imprecise then i want to know how i can do it precise.</p>
  
  <pre><code>case MotionEvent.ACTION_DOWN:
  
      lastmovex = (int) event.getX();
      lastmovey = (int) event.getY();
  
      break;
  
  case MotionEvent.ACTION_MOVE:
  
      int x = (int) event.getX(pointerindex) - lastmovex;
      int y = (int) event.getY(pointerindex) - lastmovey;
      Log.d(TAG,"move x="+x+" y="+y);
      break;
  </code></pre>
  
  <p>this show me (on finger still in one point):</p>
  
  <pre><code>move x=0 y=0
  move x=-2 y=0
  move x=0 y=0
  move x=1 y=0
  move x=-5 y=0
  move x=3 y=0
  move x=1 y=0
  move x=0 y=0
  </code></pre>
  
  <p>so, how i can get more precision or is my device with that problem? Thanks for your help</p>