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Archives of the TeradataForum
Message Posted: Thu, 20 Feb 2003 @ 11:22:28 GMT
Subj: | | Re: Random Sampling |
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From: | | Mansfield, John |
Hi Ray
I guess for a 'Truly Random' sample, you would need to connect your teradata to a truly random analogue device, like a roulette wheel or
a lotto machine. Pedantics aside, the only facilities in v2r4 for this are RANDOM and SAMPLE. Random can always be statistically tested,
(See Knuth - Seminumerical Algorithms), but this wouldn't answer any questions as to whether the method was sound. It would be nice to have
a better description of how the sequence works, is seeded etc. in the documentation. As to the statistical tests, I have performed a few on
modest sized runs on ours and found it to be adequate (i.e. it doesn't fail any chi-square frequency tests on samples of up to about size
10000 that I have tested it on)
Regards
John
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