Subject: denominator of really complicated expression
From: Ryan Krauss
Date: Tue, 22 Nov 2005 22:56:46 -0500
So, following Richard's advice, I am able to get my calculations to
run without crashing and much faster than before. I have one
additional problem though. In the end, I need to output these
expressions to a file so that they can be read into a Python program.
Running stringout(filename,expression) takes 5-15 minutes for each of
my expressions (there are currently 4 of them and it takes almost an
hour to run my script).
Is there a faster way to pass the output to Python or to save it to a
file that can be read by other programs?
Thanks,
Ryan
On 11/21/05, Richard Fateman wrote:
> put at the front:
> showtime:all$
> ratmx:true$
> nolabels:true$
> abeam:rat(abeam)$
> ratvars(abeam, cbeam, .....) ... list all the variables
>
> ...
> ratdenom(bode0);
>
>
> exclude computing stuff you don't need to compute bode0.
>
> don't use expand. all values including abeam will be expanded
> automatically, and the denominator
>
> change all the ; to $
>
> Ryan Krauss wrote:
> > I have a really complicated expression I need to find the denominator
> > of. When I save the expression to file the file is 300kb. The
> > expression has some smaller fractions sprinkled though out, so I need
> > to expand it before I can call denom. (denom on the un-expanded
> > expression just gives 1). When I call either expand or radcan on the
> > expression, it runs for several minutes, maxima takes up 300-400 megs
> > of memory and then stops with the message:
> > (%i104) bob:expand(bode0);
> >
> > Maxima encountered a Lisp error:
> >
> > Error in CATCH [or a callee]: The storage for CONS is exhausted.
> > Currently, 66689 pages are allocated.
> > Use ALLOCATE to expand the space.
> >
> > Automatically continuing.
> > To reenable the Lisp debugger set *debugger-hook* to nil.
> > (%i105)
> >
> > Does anyone have any suggestions for expanding or finding the
> > denominator of a really long expression in a way that doesn't have
> > this error?
> >
> > The attached batch file generates the expression. The expression I
> > need to simplify is called bode0.
> >
> > Thanks,
> >
> > Ryan
>
>