On Jun 10, 10:44 am, polo0691 <[EMAIL PROTECTED]> wrote:
Hi,
> Thanks for creating sage! I can really see how useful sage could be
> for engineering purposes. I've been playing around with sage for a
> couple of days and I have had trouble with the following:
>
> 1) simplifying equations with exponents:
>
> sage: var('vgs vt n')
> (vgs, vt, n)
> sage: f = (vgs - vt)^n
> sage: f^(1/n)
> ((vgs - vt)^n)^(1/n)
> sage: f^(1/n).simplify()
> ((vgs - vt)^n)^(1/n)
>
> It doesn't seem to easily simplify the exponent. I'm guessing it
> is a limitation of the CAS engine used. I also tried the same test
> case on YACAS and it didn't seem to want to simplify the exponent
> either.
Somebody else will need to answer this question.
> 2) I don't see a lot of examples on how one could take data and fit
> it to a mathematical model. I realize that I could write some python
> code and use scipy along with numpy; but I was wondering if there was
> an easier way. I'm a circuit designer and I like to fit transistor
> models within a certain range of operation to enable mathematical
> analysis of circuit operation. So the models I'm trying to fit are not
> terribly complicated (functions like above and perhaps some
> exponentials and polynomials). I've fitted functions in Excel using
> the solver function and least squares method; but was looking for more
> of a Pythonish,script based solution and then I stumbled upon Sage. I
> didn't see any examples though. I'm also interested in optimization
> algorithms that might have a place in Sage as well.
>
> 3) One of the nice things about Sage is that it interfaces to a lot
> of packages. I see the potential challenge of keeping those packages
> updated within the Sage releases. I've noticed that matplotlib, numpy,
> sympy are all out of date. For those of us who like to use the latest
> python packages, can we simply replace the older packages in the site-
> packages directories with an updated version? Is there a recommended
> way of updating incrementally small python modules without breaking
> the SAGE interface to those python modules?
It depends. Usually we do upgrade the modules shipped with Sage
quickly, but in case of numpy and scipy we are a little out of date.
numpy 1.1.0 was release a couple weeks ago and we are planning to
upgrade that in the near future. One issue holding us back that you
need to run scipy-svn at the moment since the last scipy release does
not work with numpy 1.1.0.
Feel free to report any non-current package in Sage you see and we can
then tell you if we already are aware of that release and when we are
planning to upgrade. For now:
http://trac.sagemath.org/sage_trac/ticket/3390 - upgrade numpy to
1.1.0
http://trac.sagemath.org/sage_trac/ticket/3391 - upgrade scipy to
matching release
http://trac.sagemath.org/sage_trac/ticket/3392 - upgrade matplotlib to
0.98
> thanks!
>
> Jon
Cheers,
Michael
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-support@googlegroups.com
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
-~----------~----~----~----~------~----~------~--~---
