[Numpy-discussion] RandomArray question
cnetzer at mail.arc.nasa.gov
Fri Mar 29 18:01:02 CST 2002
> <johanfo at ohman.no> writes:
>Take a look at the first number in each run !
That is because the random starting seed is (probably, I haven't looked
at the code) set from the clock, and doesn't change all that much from
run to run.
You'll see similar results when you substitute:
print "Clock at time:" , i, ":", RandomArray.random_integers(10)
print "Clock at time:" , i, ":", RandomArray.uniform(1, 10)
into your code. The part before the decimal point is always the same
on the first call of each run (assuming you run them at roughly the
Note that the 'seed' is really the internal state of the RNG and
changes at each call. You could call the random function a few dozen
times before using results, or hash the first result and use that as a
new seed, etc. But basically, the generator will produce similar
initial results (ie. one call) for similar seeds, which is what the
time value is causing.
I'd propose that the implementation, when setting the seed from the
time, generate at least one dummy RNG generation before returning
chad.netzer at stanfordalumni.org
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