Divide by Zero in precompute

[josiahseaman]

Traceback (most recent call last):
File "precompute.py", line 135, in
startRepeatMap(specimen, nProcessors)
File "precompute.py", line 89, in startRepeatMap
processors.map(precomputeRepeatMap, requests)
File "/usr/lib/python2.7/multiprocessing/pool.py", line 227, in map
50 % Complete
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return self.map_async(func, iterable, chunksize).get()
File "/usr/lib/python2.7/multiprocessing/pool.py", line 528, in get
raise self._value
ZeroDivisionError: float division by zero

This happened on both the ZmB73 and TAIR10 precomputes.