private void calculateAccelerometerRotatedRatios(ExerciseAnalyser before, 
            ExerciseAnalyser after)
    {
        ArrayList<Float> featuresBefore = before.getAccelerometerRotatedData().getFeatures(),
                featuresAfter = after.getAccelerometerRotatedData().getFeatures();
        ArrayList<String> featuresName = before.getAccelerometerRotatedData().getFeaturesName();
        
        for (int i = 0; i < featuresBefore.size(); i++)
        {
            featuresRatiosAccelerometerRotatedData.add("RATIO_" + featuresName.get(i));
            if (featuresBefore.get(i) != null && featuresAfter.get(i) != null)
            {
            Float ratio = featuresBefore.get(i) / featuresAfter.get(i);
            if (ratio.isInfinite() || ratio.isNaN())
            {
                ratio = 0.0F;
            }
            ratiosAccelerometerRotatedData.add(ratio);
            }
            else
            {
                ratiosAccelerometerRotatedData.add(null);
            }
        }
    }