Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Middle-square method
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
===In mathematics=== The method was invented by [[John von Neumann]], and was described by him at a conference in 1949.<ref name="vonneumann">The 1949 papers were not reprinted until 1951. John von Neumann, “Various techniques used in connection with random digits”, in A. S. Householder, G. E. Forsythe, and H. H. Germond, eds., ''Monte Carlo Method, National Bureau of Standards Applied Mathematics Series'', vol. 12 (Washington, D.C.: U.S. Government Printing Office, 1951): pp. 36–38.</ref> In the 1949 talk, Von Neumann quipped that "Anyone who considers arithmetical methods of producing random digits is, of course, in a state of sin." What he meant, he elaborated, was that there were no true "random numbers", just means to produce them, and "a strict arithmetic procedure", like the middle-square method, "is not such a method". Nevertheless, he found these methods hundreds of times faster than reading "truly" random numbers off [[punch cards]], which had practical importance for his [[ENIAC]] work. He found the "destruction" of middle-square sequences to be a factor in their favor, because it could be easily detected: "one always fears the appearance of undetected short cycles".<ref name="vonneumann"/> [[Nicholas Metropolis]] reported sequences of 750,000 digits before "destruction" by means of using 38-bit numbers with the "middle-square" method.<ref>Donald E. Knuth, ''The art of computer programming, Vol. 2, Seminumerical algorithms'', 2nd edn. (Reading, Mass.: Addison-Wesley, 1981), ch. 3, section 3.1.</ref> The book ''The Broken Dice'' by [[Ivar Ekeland]] gives an extended account of how the method was invented by a Franciscan friar known only as Brother Edvin sometime between 1240 and 1250.<ref name="Ekeland1996">{{cite book |author=Ivar Ekeland |title=The Broken Dice, and Other Mathematical Tales of Chance |date=15 June 1996 |publisher=University of Chicago Press |isbn=978-0-226-19992-4}}</ref> Supposedly, the manuscript is now lost, but [[Jorge Luis Borges]] sent Ekeland a copy that he made at the Vatican Library. Modifying the middle-square algorithm with a [[Weyl sequence]] improves period and randomness.<ref>{{cite book | title = Random Numbers and Computers | last = Kneusel | first = Ron | publisher = Springer | year = 2018 | edition = 1 | pages = 13–14 }}</ref><ref>{{cite arXiv | last=Widynski | first=Bernard | eprint=1704.00358 | title=Middle-Square Weyl Sequence RNG | date=April 2017| class=cs.CR }}</ref>
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)