The distinction that may be worth making is that there are (at least)
two
notions of factorial. One that is subject to symbolic simplification
and one
that is a numerical subroutine. There may be yet more.
The simplification version allows for
factorial(n+1)/factorial(n) ---> n+1 and does not r
Hi there,
> > In Sage, the behavior of sqrt(2) versus sqrt(4) is considered very
> > reasonable
> > to most users. And it does exactly what you claim is "rather bad form".
> >
> > sage: sqrt(2)
> > sqrt(2)
> > sage: sqrt(4)
> > 2
> > sage: type(sqrt(2))
> >
> > sage: type(sqrt(4))
> >
>
On Jun 17, 12:51 pm, William Stein wrote:
> In Sage, the behavior of sqrt(2) versus sqrt(4) is considered very reasonable
> to most users. And it does exactly what you claim is "rather bad form".
>
> sage: sqrt(2)
> sqrt(2)
> sage: sqrt(4)
> 2
> sage: type(sqrt(2))
>
> sage: type(sqrt(4))
>
Th
On Thu, Jun 17, 2010 at 12:14 PM, Nils Bruin wrote:
> On Jun 17, 10:32 am, Robert Dodier wrote:
>> On Jun 16, 11:24 am, Tom Coates wrote:
>>
>> > A) factorial(x) should raise an error;
>>
>> > B) factorial(x) should return gamma(x+1).
>>
>> More generally, the question is what to do with somet
On Jun 17, 10:32 am, Robert Dodier wrote:
> On Jun 16, 11:24 am, Tom Coates wrote:
>
> > A) factorial(x) should raise an error;
>
> > B) factorial(x) should return gamma(x+1).
>
> More generally, the question is what to do with something
> which doesn't make sense according to whatever rules ha
On Jun 16, 11:24 am, Tom Coates wrote:
> A) factorial(x) should raise an error;
>
> B) factorial(x) should return gamma(x+1).
More generally, the question is what to do with something
which doesn't make sense according to whatever rules have
been established so far. I claim the "mathematical"
On Jun 17, 3:07 am, David Kirkby wrote:
...
> BTW, the #6 hit for factorial in Google, and the number 1 hit for
> factorial calculator is this
>
> http://www.cs.uml.edu/~ytran/factorial.html
>
> One might have hoped a professor of computer science could have done a
> bit better.
1. It appears
It is my recollection that the definition of sqrt of a negative
number, say -9, in the unix math library
is the sqrt of abs value. Hence it returns 3. So that's another
choice.
Contrary to Tom's note, I am not requiring that the range and domain
of a function be the same,
though it may have appea
On 16 June 2010 15:48, rjf wrote:
>
>
> On Jun 15, 9:28 pm, Tom Coates wrote:
>
> By your reasoning, and for other domains we would have the following
> behavior:
> sqrt(-1) --> error. after all, some Sage users may not have
> encountered imaginary numbers.
> RJF
That's a very weak argument.
On Wed, 16 Jun 2010 at 01:58PM -0400, Jason Bandlow wrote:
> > At the moment there does not seem to be a clear consensus either way.
> > If you have an opinion on this, please vote! Let x be an explicit
> > numerical value such that x is not a non-negative integer (e.g. x=2/3,
> > x=1.5, or x=i).
On 16 June 2010 18:24, Tom Coates wrote:
> At the moment there does not seem to be a clear consensus either way.
> If you have an opinion on this, please vote! Let x be an explicit
> numerical value such that x is not a non-negative integer (e.g. x=2/3,
> x=1.5, or x=i). The options are:
>
> A)
On 2010-Jun-16 10:24:35 -0700, Tom Coates wrote:
>That said, if the consensus is that factorial(x) should be
>analytically continued, to allow x to be an explicit non-integral
>number (as is the case in Maple and Mathematica), then I am happy with
>this. But then we should change the documentatio
> At the moment there does not seem to be a clear consensus either way.
> If you have an opinion on this, please vote! Let x be an explicit
> numerical value such that x is not a non-negative integer (e.g. x=2/3,
> x=1.5, or x=i). The options are:
>
> A) factorial(x) should raise an error;
>
>
> At the moment there does not seem to be a clear consensus either way.
> If you have an opinion on this, please vote! Let x be an explicit
> numerical value such that x is not a non-negative integer (e.g. x=2/3,
> x=1.5, or x=i). The options are:
>
> A) factorial(x) should raise an error;
>
> B
On 16 June, 07:48, rjf wrote:
> By your reasoning, and for other domains we would have the following
> behavior:
>
> 1-2 --> error. 1 and 2 are both positive integers. In order to
> provide the answer -1, one must
> expand the domain to include negative integers.
>
> 1 / 2 --> error..
On Jun 15, 9:28 pm, Tom Coates wrote:
>
...
>
> I have not thought seriously about the issues involved, so my opinion
> should be regarded as tentative. But right now my view is that the
> symbolic expressions factorial(x) and gamma(x+1) should not be
> identified, and that factorial(x) should
16 matches
Mail list logo
