Re: Random Numbers

Steven G. Kargl <kargl@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

[ wants random numbers reproducible from run to run ]
OTOH, I do use code of the form

call random_seed(size=n)
allocate(put(n))
put = nrand + 37 * (/ (i - 1, i = 1, n) /) ! nrand is user input.
call random_seed(put=put)
deallocate(put)

Does the standard specify what you can or cannot pass to
random_seed(put=) ? I mean the content, not just the size. I was
bitten once by an implementation that was very picky about the
contents of its seed vectors. I did as you show, asking random_seed()
for the size and filling the array with some sequence salted by a
small user input. The resulting sequence was anything but random !

IIRC the standard promises that you can call random_seed(get=) and
use the result in a random_seed(put=), but as far as I know you
can't construct your own seed.


--
pa at panix dot com
.

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