[Numpy-tickets] [NumPy] #488: seeded randint returns different values on 32 and 64bit architectures
NumPy
numpy-tickets@scipy....
Mon Apr 2 07:10:41 CDT 2007
#488: seeded randint returns different values on 32 and 64bit architectures
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Reporter: benstone | Owner: somebody
Type: defect | Status: closed
Priority: normal | Milestone:
Component: numpy.random | Version: 1.0.1
Severity: normal | Resolution: fixed
Keywords: randint |
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Changes (by cookedm):
* status: new => closed
* resolution: => fixed
Old description:
> This returns different values on 32 and 64bit Ubuntu (feisty) - using
> Numpy1.0.1
> import numpy.random as r
> r.seed(7777)
> r.randint(10)
New description:
This returns different values on 32 and 64bit Ubuntu (feisty) - using
Numpy1.0.1
{{{
import numpy.random as r
r.seed(7777)
r.randint(10)
}}}
Comment:
The underlying Mersenne Twister RNG gives out 32-bit integers per call. On
a 64-bit machine, it'll be called twice to make a 64-bit integer. I've
changed it in r3642 so that intervals less than 2**32 on a 64-bit machine
will use one call to the RNG, instead of two.
Has the side effect that randint will be faster on 64-bit machines now.
--
Ticket URL: <http://projects.scipy.org/scipy/numpy/ticket/488#comment:1>
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