Deutsch English Français Italiano |
<v73r04$ql49$2@dont-email.me> View for Bookmarking (what is this?) Look up another Usenet article |
Path: ...!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: HenHanna <HenHanna@devnull.tb> Newsgroups: comp.lang.python,sci.math,sci.lang Subject: Re: (1 Combination 2) = 0 -- Better explanation? Date: Mon, 15 Jul 2024 11:49:39 -0700 Organization: A noiseless patient Spider Lines: 47 Message-ID: <v73r04$ql49$2@dont-email.me> References: <v71e3t$a766$1@dont-email.me> <v725uv$hnvc$1@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 15 Jul 2024 20:49:41 +0200 (CEST) Injection-Info: dont-email.me; posting-host="9f40a81de22b763cca63bc8ade3e003e"; logging-data="873609"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19bqjt5aXxBRYHbUCZ8dHlFi+M/FnguBX0=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:htIucn9sc28nBbWijMyYPWJdnSE= Content-Language: en-US In-Reply-To: <v725uv$hnvc$1@dont-email.me> Bytes: 2403 On 7/14/2024 8:44 PM, Jeff Barnett wrote: > On 7/14/2024 2:57 PM, HenHanna wrote: >> >> Python says: (1 Combination 2) = 0 >> >> Ok... It's Impossible (to do). >> >> ------- is there a Better explanation? >> >> >> >> (5 Combination 0) = 1 <---- This is explained by Comb(5,0)=Comb(5,5) >> >> in general: Comb(N,r)=Comb(N,N-r) >> >> _______________________________________ >> >> from math import comb >> >> for i in range(6): print( comb(5,i) ) >> >> print( comb(1,2) ) > > Let combination of n things taken m at a time be represented by [n,m]. > Then [n,m] = [n,n-m] as you correctly note above. Further, we have the > computational formula [n,m] = n!/(m!(n-m)!) where x! is simply x > factorial. So [1,2] = 1!/(2!((-1)!)), or 1/2 divided by (-1)!. However > factorial of a negative integer is, by convention, an infinite value so > [1.2] = 0. THank you... Bard.Google.com says that Comb(1,2) is not defined factorial(-1) is not defined factorial(-2) is not defined GammaFunction(-1) is not defined GammaFunction(-2) is not defined