private void saveTouchStart(MotionEvent event){
  mSavedMatrix.set(mMatrix);
  mTouchStartPoint.set(event.getX(),event.getY());
  mClosestDataSetToTouch=mChart.getDataSetByTouchPoint(event.getX(),event.getY());
}

private void saveTouchStart ( MotionEvent event ) { mSavedMatrix . set ( mMatrix ) ; mTouchStartPoint . set ( event . getX ( ) , event . getY ( ) ) ; mClosestDataSetToTouch = mChart . getDataSetByTouchPoint ( event . getX ( ) , event . getY ( ) ) ; }
saves the current matrix state and the touch - start point .
