Thread

Re: [HACKERS] random() function produces wrong range

Roland Roberts <roberts@panix.com> — 2000-08-03T15:18:34Z

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>>>>> "Thomas" == Thomas Swan <tswan@olemiss.edu> writes:

    Thomas> Is it possible to test (during configure phase) and then
    Thomas> go from there...  or does it need to be the same for all
    Thomas> platforms?

You should be able to test, but it is, of course, a statistical test.
Call random() several times and test the maximum value against your
thresholds of 2^15 and 2^31.  If random() is generating values in the
range 1:2^31-1, you would expect half of your values to be greater
than 2^15-1; more importantly, if you generate, say, 10 values, you
expect only a 1:1024 chance that they are all below 2^15.  If those
odds aren't good enough, generate more.

roland
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Roland B. Roberts, PhD                    Unix Software Solutions
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