#4163: tut -- improve factorial / valuation example
---------------------------+------------------------------------------------
Reporter: was | Owner: tba
Type: enhancement | Status: new
Priority: minor | Milestone: sage-3.1.3
Component: documentation | Keywords:
---------------------------+------------------------------------------------
{{{
That's a good point.
2008/9/20 pong <wypong00>:
>
> This is not a bug report. But I'm not sure where to post a suggestion.
>
> In the SAGE tutorial, http://www.sagemath.org/doc/tut/node27.html
>
> there is an example:
>
> sage: c = factorial(25); c
> 15511210043330985984000000
> sage: [valuation(c,p) for p in prime_range(2,23)]
> [22, 10, 6, 3, 2, 1, 1, 1]
>
> Since prime_range(2,23) does not include 23 itself, maybe it's better
> to change it to prime_range(2,25). In that case, the product of primes
> to the corresponding powers will actually give the factorial of 25.
I would also include
sage: c.factor()
2^22 * 3^10 * 5^6 * 7^3 * 11^2 * 13 * 17 * 19 * 23
(which would be helpful to people who might know know this meaning of
"valuation", standard in number theory), and even perhaps
sage: list(c.factor())
[(2, 22), (3, 10), (5, 6), (7, 3), (11, 2), (13, 1), (17, 1), (19, 1),
(23, 1)]
John Cremona
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/4163>
Sage <http://sagemath.org/>
Sage - Open Source Mathematical Software: Building the Car Instead of
Reinventing the Wheel
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en
-~----------~----~----~----~------~----~------~--~---
