Thanks for the help provided so far, but I have encountered a new
problem that I've been unable to solve: a second-order DE with
constant but *complex* coefficients:
y'' + (1 - i)y' - iy = 0
sage: maxima.de_solve('derivative(y,x,2) + (1 - i) * derivative(y,x)
- i * y = 0', ['x','y'])
yields:
Exception (click to the left for traceback):
...
Is i+1 zero or nonzero?
Looking at the maxima documentation, there appears to be a way to
tell maxima maxima.assume('i+1 <> 0'), but this syntax seems to send
sage into the ozone.
Thanks in advance for help offered.
Jim Clark
On Mar 21, 2008, at 5:29 PM, David Joyner wrote:
>
> If your main interest is in solving DEs using SAGE, then you might be
> interested in the material on
> http://sage.math.washington.edu/home/wdj/teaching/index.html
> You may also be interested in joining sage-edu, which is
> unfortunately not on http://www.sagemath.org/lists.html
> but can be found here: http://groups.google.com/group/sage-edu
>
>
> On Fri, Mar 21, 2008 at 5:15 PM, Jim Clark
> <[EMAIL PROTECTED]> wrote:
>> Hello SAGE people:
>>
>> I want to report a problem I encountered in my attempts to learn
>> SAGE
>> via the tutorial.
>>
>> First of all, I installed SAGE on my home computer, an iMac with
>> OS X
>> 10.4.
>>
>> I have been running the documentation by way of the "help" link in
>> the notebook.
>>
>> When I came to differential equations, this is what I saw on my
>> screen:
>>
>>
>>>
>>
>>
>>
>> This was puzzling, to say the least. (It has taken quite a bit of
>> effort to discover how to solve simple differential equations...)
>>
>> Along the way I decided to check out the documentation from the
>> sagemath.org home page. The tutorial is presented differently. The
>> same example appears:
>>
>>
>>
>>
>> It made a lot more sense when I could see the equations!
>>
>> Has this problem with the "live" tutorial been recorded? Is someone
>> working on it?
>>
>> I also have an opinion: This example is much too complicated for the
>> tutorial. I think the tutorial should first present a single, simple
>> DE before diving into systems of DEs.
>>
>> Furthermore, I have an additional gripe, coming into SAGE with no
>> knowledge whatsoever of the systems that SAGE is built upon. It
>> appears that solving differential equations depends on something
>> called maxima, about which I initially knew nothing (a Google search
>> has now taught me a bit about what it is, but it appears that if I
>> want to solve differential equations, then I must learn maxima in
>> addition to SAGE.)
>>
>> At any rate, I would have found it helpful in the tutorial if there
>> were a bit of explanation of this relationship of SAGE to the
>> various
>> subsystems, perhaps with tables showing which subsystems do what,
>> when one needs to be explicit about invoking the subsystem and how
>> one goes about such invocation from SAGE.
>>
>> At any rate, thanks for all you are doing. I hope that, by sharing
>> the difficulties I have encountered coming into SAGE completely
>> cold,
>> you will be able to improve your product.
>>
>> Jim Clark
>>
>>
>>
>
> >
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