| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> |
| Cc: | andrew(at)supernews(dot)com, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Bug: random() can return 1.0 |
| Date: | 2006-01-19 23:26:09 |
| Message-ID: | 10560.1137713169@sss.pgh.pa.us |
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| Lists: | pgsql-hackers pgsql-patches |
Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> Because random returns a double, I think it is very possible that we
> could return 1 due to rounding,
Not unless your machine has a "double" type with less than 32 bits of
precision, which seems pretty unlikely. It'd be sufficient to do
/* result 0.0 <= x < 1.0 */
result = ((double) random()) / ((double) MAX_RANDOM_VALUE + 1.0);
regards, tom lane
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