Hi Jason,
On Fri, 18 Sep 2009 13:15:46 -0500
Jason Grout <[email protected]> wrote:
>
> On alpha.sagenb.org, I get the following:
>
> sage: t=var('t')
> sage: diff(cot(t),t)
> D[0](cot)(t)
> sage: diff(cos(t)/sin(t),t)
> -cos(t)^2/sin(t)^2 - 1
>
>
> Does Sage not know that cot(t) is cos(t)/sin(t)? Or am I just being
> silly?
Unfortunately it doesn't.
GiNaC doesn't define the function cot. Sage defines it in the file
sage/functions/trig.py starting at line 184. I suppose it was written
quickly by Mike during the symbolics switch.
Defining a custom derivative function (named _derivative_()) in that
class should fix this.
I opened a ticket:
http://trac.sagemath.org/sage_trac/ticket/6956
Thanks.
Burcin
--~--~---------~--~----~------------~-------~--~----~
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-support
URLs: http://www.sagemath.org
-~----------~----~----~----~------~----~------~--~---
