Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.java.programmer > #33933
| From | Andreas Leitgeb <avl@logic.at> |
|---|---|
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: Random permutations [was Re: Libraries for sysadmins?] |
| Date | 2016-03-05 18:30 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <slrnndm9jm.456.avl@login.logic.tuwien.ac.at> (permalink) |
| References | (3 earlier) <dju62bFf4ouU1@mid.individual.net> <concise-20160304210431@ram.dialup.fu-berlin.de> <nbd7c3$3jp$1@news.albasani.net> <djvt76Fs5qfU2@mid.individual.net> <nbeunm$drn$1@news.albasani.net> |
Sebastian <news@seyweiler.dyndns.org> wrote: > Am 05.03.2016 12:11, schrieb Robert Klemme: >> On 05.03.2016 00:56, Sebastian wrote: >>> new Random().ints(1, 50).distinct().limit(6) >> Are you sure this has the same probability characteristics as picking >> six random items from a list of 49? > I think yes, because Random#ints() is evenly distributed. Maybe similar enough for almost all practical purposes, but strictly speaking, the distinct() might pass through a set of less than 6 different ints. Anyone care to calculate the probability of that happening? I'm too lazy (and my skill too rusty by now), to do it myself. > And as I said, > this is useful when the range is much larger than the sample > size. A way to deal with extremes, like "2 out of 42 tredecillions" would be to pick one number n1 out of the whole range, and then a second number n2 of the range reduced by 1. Then compare the numbers, and add 1 to n2, if it is greater or equal to n1. Once again I'm too lazy to type out the procedure for a 3rd, 4th, ..., k'th number, but it's no rocket science, anyway. Not sure, if there are any ready-made filters for producing random numbers from a decreasing range, and for re-adjusting numbers depending on previous picks.
Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Libraries for sysadmins? Elena <egarrulo@gmail.com> - 2016-03-04 03:33 -0800
Re: Libraries for sysadmins? Martin Gregorie <martin@address-in-sig.invalid> - 2016-03-04 11:44 +0000
Re: Libraries for sysadmins? egarrulo <egarrulo@gmail.com> - 2016-03-04 12:56 +0100
Re: Libraries for sysadmins? Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-03-04 07:43 -0500
Re: Libraries for sysadmins? Robert Klemme <shortcutter@googlemail.com> - 2016-03-04 18:06 +0100
Re: Libraries for sysadmins? egarrulo <egarrulo@gmail.com> - 2016-03-04 20:30 +0100
Random permutations [was Re: Libraries for sysadmins?] Sebastian <news@seyweiler.dyndns.org> - 2016-03-05 00:56 +0100
Re: Random permutations [was Re: Libraries for sysadmins?] Robert Klemme <shortcutter@googlemail.com> - 2016-03-05 12:11 +0100
Re: Random permutations [was Re: Libraries for sysadmins?] Sebastian <news@seyweiler.dyndns.org> - 2016-03-05 16:41 +0100
Re: Random permutations [was Re: Libraries for sysadmins?] Brixomatic <brixomatic@yahoo.com> - 2016-03-05 19:20 +0100
Re: Random permutations [was Re: Libraries for sysadmins?] Andreas Leitgeb <avl@logic.at> - 2016-03-05 18:46 +0000
Re: Random permutations [was Re: Libraries for sysadmins?] Brixomatic <brixomatic@yahoo.com> - 2016-03-15 19:22 +0100
Re: Random permutations [was Re: Libraries for sysadmins?] Andreas Leitgeb <avl@logic.at> - 2016-03-15 22:30 +0000
Re: Random permutations [was Re: Libraries for sysadmins?] Andreas Leitgeb <avl@logic.at> - 2016-03-05 18:30 +0000
Re: Random permutations [was Re: Libraries for sysadmins?] Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-03-05 13:46 -0500
Re: Random permutations [was Re: Libraries for sysadmins?] Andreas Leitgeb <avl@logic.at> - 2016-03-05 19:40 +0000
Re: Libraries for sysadmins? Robert Klemme <shortcutter@googlemail.com> - 2016-03-05 12:10 +0100
Re: Libraries for sysadmins? Arne Vajhøj <arne@vajhoej.dk> - 2016-03-04 21:42 -0500
Re: Libraries for sysadmins? Arne Vajhøj <arne@vajhoej.dk> - 2016-03-04 21:48 -0500
csiph-web