[sage-support] Random sum of functions

2013-07-17 Thread Laurent Decreusefond
Hi everyone, say I have a function of both an integer n and a complex z def f(n,z): return z**n For any tuple of integer (a_1,a_2, ..., a_k), (actually, k and a_i are random), I want to form the function z - sum_{i=1}^k |f(a_i, z)|^2 The result must still be a function. I guess it is

[sage-support] Longest Common Subsequence

2013-07-17 Thread Nathann Cohen
Helloo everybody !!! Is there a way to compute the longest common subsequence of two (binary) words in Sage ? I can't find how, but it looks like something Sage should be able to do :-) Thaanks ! Nathann -- You received this message because you are subscribed to the Google Groups

Re: [sage-support] Random sum of functions

2013-07-17 Thread D. S. McNeil
I don't think you need to make an explicit class here. You can build a function from within another function, and return that: sage: def f(n, z): : return z**n : sage: def maker(tup): : def g(z): : return sum(abs(f(a_i,z))**2 for a_i in tup) : return g

Re: [sage-support] Re: Trouble with easy_install

2013-07-17 Thread Viviane Pons
Thank's, indeed I went thought the all thing and now it works! 2013/7/17 P Purkayastha ppu...@gmail.com On 07/16/2013 05:35 PM, Viviane Pons wrote: Hi everyone, I have installed sage-5.11-beta3 and for some reason, I cannot use use easy_install anymore on the sage shell. It seems to be a

Re: [sage-support] Random sum of functions

2013-07-17 Thread Anton Sherwood
On 2013-7-17 02:07, Laurent Decreusefond wrote: For any tuple of integer (a_1,a_2, ..., a_k), [...] I want to form the function z - sum_{i=1}^k |f(a_i, z)|^2 Won't this work? def ff(atuple,z): return sum([ abs(f(n,z))**2 for n in atuple ]) -- *\\* Anton Sherwood

Re: [sage-support] Digest for sage-support@googlegroups.com - 5 Messages in 3 Topics

2013-07-17 Thread Carl Eberhart
Hi Nathann Here is a Wikipedia article with what looks very much like the python code for a solution. http://en.wikipedia.org/wiki/Longest_common_subsequence_problem Carl On Wed, Jul 17, 2013 at 12:11 PM, sage-support@googlegroups.com wrote: Today's Topic Summary Group:

[sage-support] Error summing inverses of binomial coefficients

2013-07-17 Thread Ed Scheinerman
I am looking to evaluate $\sum_{k=0}^n 1/\binom{n}{k}$ so I type: sage: n = var('n') sage: k = var('k') sage: sum(1/binomial(n,k),k,0,n) (n + 1)*2^(-n) and that answer is wrong. For example, with n=10 we get sage: sum(1/binomial(10,k) for k in range(11)) 1433/630 but the alleged answer of