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generating random numbers -- what seeds to use?
From: |
John W. Eaton |
Subject: |
generating random numbers -- what seeds to use? |
Date: |
Sun, 27 Apr 2003 20:03:41 -0500 |
On 27-Apr-2003, Mike Miller <address@hidden> wrote:
| I need to create large amounts of random data under a certain model. I
| wanted to produce 10,000 files, so I set 10 different processors to the
| task of executing an octave scrit that would make 1,000 files.
| Unfortunately, I forgot that some of the jobs were starting at nearly the
| same moment, so they took the same seed from the clock and produced the
| same 'random' files!
|
| I'd still like to run 10 jobs at once, but I'll have to supply initial
| seeds. Is there any way that I can guarantee that I won't produce the
| same file twice? What is the best way to choose seeds? What is the
| period for Octave's random number generator? Has anyone developed other
| random number generators for Octave?
Why not generate all the random numbers in advance? For example, for
N random numbers in each of M files, something like
for i = 1:M
f = fopen (sprintf ("rnd-%d", i), "w");
fwrite (f, rand (N, 1), "double");
fclose (f);
endfor
Then you could read these files for your data generation processes.
jwe
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