public double calcAngleWithRatios(Entry p1,Entry p2){
  float dx=p2.getXIndex() * mDeltaRatio - p1.getXIndex() * mDeltaRatio;
  float dy=p2.getVal() * mScaleRatio - p1.getVal() * mScaleRatio;
  return Math.atan2(dy,dx) * 180.0 / Math.PI;
}

public double calcAngleWithRatios ( Entry p1 , Entry p2 ) { float dx = p2 . getXIndex ( ) * mDeltaRatio - p1 . getXIndex ( ) * mDeltaRatio ; float dy = p2 . getVal ( ) * mScaleRatio - p1 . getVal ( ) * mScaleRatio ; return Math . atan2 ( dy , dx ) * 180.0 / Math . PI ; }
calculates the angle between two entries ( points ) in the chart taking ratios into consideration
