Hi Francois,
On Thu, 07 Oct 2010 22:39:38 +0200
Francois Maltey <fmal...@nerim.fr> wrote:
> Now I want to test an expression with the binomial function call.
>
> y = binomial (3*x, x) # is fine
> op = y.operator() # is also fine
> op # I get binomial
> op == binomial # remains False
The top level binomial() function is the one defined in
sage.rings.arith. The symbolic binomial function is defined in
sage.functions.other:
sage: SR(2).binomial(x)
binomial(2, x)
sage: SR(2).binomial(x).operator().__module__
'sage.functions.other'
sage: binomial.__module__
'sage.rings.arith'
It looks like the top level binomial() function is a mess already.
- binomial does not accept variable when only in the lower argument
http://trac.sagemath.org/sage_trac/ticket/9634
- binomial does not accept float
http://trac.sagemath.org/sage_trac/ticket/9633
Looking at the code in sage/rings/arith.py, I see that the if statement
starting at line 2999 is a duplicate of that in at line 2961.
Replacing the top level binomial function with the symbolic one defined
in sage.functions.other should provide an easy fix for all these
problems. I wonder if it effects the speed too much.
> How can I do this test for binomial ?
As a workaround you can test if the operator is the function defined in
sage.functions.other.
sage: y = binomial(3*x, x)
sage: y.operator()
binomial
sage: y.operator() is sage.functions.other.binomial
True
Cheers,
Burcin
--
To post to this group, send an email to sage-devel@googlegroups.com
To unsubscribe from this group, send an email to
sage-devel+unsubscr...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/sage-devel
URL: http://www.sagemath.org
