In article <[EMAIL PROTECTED]>, David Heiser <[EMAIL PROTECTED]> wrote:
>"CybercafeUser" <[EMAIL PROTECTED]> wrote in message >news:[EMAIL PROTECTED] >> Excel's help mentions the Abramovitz (1969?) which you can also find as a >> ref in 25 years old HP calculators. >> It is not enough for most applications. The one in the addind for >> statistical analysis seems to be different but Microsoft never answered my >> questions; >> Yves >Abramowitz is sort of a icon. Every time you see this platinum icon, it >refers to the classic publication of the old National Bureau of Standards in >1963. Dover republishes it, so it is still in print. It is the gold standard >on nummerical algorithms, and all kinds of everything else. My copy is dog >chewed (one corner) and just about worn out. Abramowitz has some useful tables, but its approximations, etc., are quite dated and not all that useful. It is an old icon. >Excel used RAND as a worksheet cell function. It is a very simple one liner, >very fast, and gives in most situations an acceptable result. Microsoft gave >out the algorithm. There is a lot of RNG pedelling out there, and even more >opinions on RAND. I believe you will find almost all of them bad. >The random number generator in the data analysis toolpak is different, one >that was not invented by Microsoft, and Microsoft apparently cannot divulge >it. It appears to be a simple congruential generator on a 16 bit integer. >Has a short period. In general, don't use it. Dates back to the 1980's when >anything programed for a computer was automatically accepted as being "the >cat's meow". If it is as you have stated, anyone could crack it. Even long period generators can be rather bad; I personally have a great mistrust for pseudo-random number generators. -- This address is for information only. I do not claim that these views are those of the Statistics Department or of Purdue University. Herman Rubin, Department of Statistics, Purdue University [EMAIL PROTECTED] Phone: (765)494-6054 FAX: (765)494-0558 . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
