def findOverlap(self, a, b, dur):
"""Utility for returning the fraction of given duration that
is spent in the overlap of the two given tuples.
"""
a1, a2 = a
b1, b2 = b
# what's the overlap between them (like the Galactice Center)?
if AnalogSet.overlaps(a, b):
ints = AnalogSet.intersect(a, b)
# if our range is entirely in overlap, avoid calculations
if self.fltEqual(ints[0], a1) \
and self.fltEqual(ints[1], a2):
overlap = dur
nonOverlap = 0
else:
# otherwise we need to convert back to duration -
# one way to do this is via fractions
frac = (ints[1] - ints[0]) / (a2 - a1)
overlap = dur * frac
nonOverlap = (1.0 - frac) * dur
else:
overlap = 0
nonOverlap = dur
return (overlap, nonOverlap)
