On 16 June 2010 15:48, rjf fate...@gmail.com wrote:
On Jun 15, 9:28 pm, Tom Coates t.coa...@imperial.ac.uk 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.
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
On Jun 17, 3:07 am, David Kirkby david.kir...@onetel.net 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
On Jun 16, 11:24 am, Tom Coates t.coa...@imperial.ac.uk 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
On Jun 17, 10:32 am, Robert Dodier robert.dod...@gmail.com wrote:
On Jun 16, 11:24 am, Tom Coates t.coa...@imperial.ac.uk 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
On Thu, Jun 17, 2010 at 12:14 PM, Nils Bruin nbr...@sfu.ca wrote:
On Jun 17, 10:32 am, Robert Dodier robert.dod...@gmail.com wrote:
On Jun 16, 11:24 am, Tom Coates t.coa...@imperial.ac.uk wrote:
A) factorial(x) should raise an error;
B) factorial(x) should return gamma(x+1).
More
On Jun 17, 12:51 pm, William Stein wst...@gmail.com 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))
type
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))
type 'sage.symbolic.expression.Expression'
sage:
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
On 16 June, 07:48, rjf fate...@gmail.com 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 --
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)
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 2010-Jun-16 10:24:35 -0700, Tom Coates t.coa...@imperial.ac.uk 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
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