Suppose there are 2 routines, each will initialize the seed and call ? alternatively, because state of rng is global, what a routine will get depend on the other routine or the cache left. There is a possibility that the sequence got by a routine does not satisfy original statistical property of randomness.
suppose rng give 0 1 0 1 0 1 0 1 0 1 ..... for calling ?2 repeatedly then routine a get 0 0 0 0 0 ... while routine b get 1 1 1 1 1 ... originally it should be bi-modal and average 0.5, of course any respectable rng will not generate this sequence, but it might illustrate the problem. So, is it possible to make 2 independent instances of ? for private use? regards, bill ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
