[Numpy-tickets] [NumPy] #581: random.set_state does not reset state of random.standard_normal
NumPy
numpy-tickets@scipy....
Mon Sep 17 10:31:44 CDT 2007
#581: random.set_state does not reset state of random.standard_normal
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Reporter: Yung-Chin Oei | Owner: somebody
Type: defect | Status: new
Priority: normal | Milestone:
Component: numpy.random | Version: 1.0.1
Severity: normal | Keywords:
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When calling random.set_state the function random.standard_normal may
return an internally retained old number before starting to use the new
state of the generator.
I think this happens because the Box-Muller algorithm generates normally
distributed numbers in pairs. If an uneven number of calls to the function
was made before using set_state, the second number of such a pair is
returned before new numbers are generated.
Maybe useful for fixing this problem: using random.seed(0) does seem to
properly reset the internal state of random.standard_normal - the next
call to standard_normal always returns the expected new random number.
--
Ticket URL: <http://scipy.org/scipy/numpy/ticket/581>
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