On Thu, Feb 17, 2011 at 1:30 PM, Jeff <mailjeffw...@googlemail.com> wrote:
> To be consistent with the assumption, though, I think that iimag(a)
> should return zero.
>
> Can anyone comment?
Unfortunately, the assumptions system (still) is not well integrated
with the Pynac code. When you do assume(a, 'real'), it sends that
assumption to Maxima, and Sage/Pynac does not really know anything
about it. In order for it to be "in effect", you have to send the
expression to Maxima and ask it to simplify it:
sage: var('a')
a
sage: assume(a, 'real')
sage: imag(a)
imag_part(a)
sage: imag(a).simplify()
0
Additionally, you can specify the "domain" (complex, real, positive)
of a variable within Pynac directly by doing
sage: a = var('a', domain=RR)
sage: imag(a)
0
However, this does not create the corresponding assumption within Maxima.
--Mike
--
To post to this group, send email to sage-support@googlegroups.com
To unsubscribe from this group, send email to
sage-support+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/sage-support
URL: http://www.sagemath.org
