don@allegra.UUCP (D. Mitchell) (04/22/84)
My statement was not misleading. "random()" as distributed, is very poor. While Mr. Cohen says he ran extensive checks, I found it badly failed simple correlation tests. I use my own generator (which I posted) so I just forgot about it. A few days later, Jim Reeds ran some tests and actually predicted the bug on the basis of those test, which we then found. (That is, the use of a polynomial that was not irreducible) I would say with the bug fixed, random() is just fine. If you want floating point numbers, I would recommend my frandom(). It generates a full 56-bit random mantissa, and is therefore much better (and much faster) than dividing an integer random number by (double)2**31.
gwyn@BRL-VLD.ARPA (04/26/84)
From: Doug Gwyn (VLD/VMB) <gwyn@BRL-VLD.ARPA> There are also the routines described in DRAND48(3C) (not available on 4.2BSD as distributed). set $ANSWER=$< to read ANSWER There may be other bugs too but this should help.