'**SUMMARY**
Returns a numpy array of the areaRatio of each feature.
where areaRatio is the ratio of the size of the current bounding box to
the size of the initial bounding box
**RETURNS**
A numpy array.
**EXAMPLE**
>>> while True:
... img1 = cam.getImage()
... ts = img1.track("camshift", ts1, img, bb)
... img = img1
>>> print ts.areaRatio'

def areaRatio(self):

    return np.array([f.areaRatio for f in self])
