Dear all,
I found that as I asked the nonlinear equation solution for more ram I have
unintentionally missformulated the problem and write in ex k27 instead of
k72. Now I had the solution. I would like to say that it is very easy to
compile maxima with clisp. I have done it under cygwin and there was no ram
barrier. As a recommendation I would like to say that can the newer builds
for windows be compiled with clisp for not to confront the same ram
problems. I am sure it would be easy for the developers to compile with
msys-mingw environment with clisp. Also I want to comment that I had a
relatively small system of equation and while I did not investigated the
equations by simplifying them I did not discovered that the problem was
linear. When I formulated this with the linear solving the solution resulted
very quickly. However the nonlinear solver did not checked for linear terms
and thus the solution took more than the linear one. Would not it be good to
check for any linear equations to first eliminate the linear terms instead
of going from first to last in maxima?
Thanks in advance...
Regards
Ahmet Alper Parker
On 5/20/07, ahmet alper parker <aaparker at gmail.com> wrote:
>
> Thanks Richard but I would like to solve this one :) Thanks for your
> valuable comments :)
> Ahmet Alper Parker
>
> On 5/19/07, Richard Fateman < fateman at cs.berkeley.edu> wrote:
> >
> > 1. Your problem is to solve a set of non-linear equations. A program
> > which is claimed to be efficient for this is Singular.
> > Unless there is some special structure to the solution, it will probably
> > not be possible to find it in closed form, regardless of the computer
> > language or hardware you use.
> > 2. Exploiting parallel computing on a supercomputer is probably
> > irrelevant. There are papers (indeed, whole conferences) about parallel
> > algebraic computation, and parallel Grobner basis computations. There are
> > some lisps that support parallel computation, but Maxima does not make
> > particular use of these features because Maxima operates largely in a common
> > subset of Lisp (i.e. essentially ANSI Common Lisp). But your problems
> > probably take exponentially more time and space, e.g. doubling when you
> > go from 28 to 29 variables; doubling again when you go from 29 to 30 ...
> > 3. MockMMA will not be especially more useful than Maxima.
> > 4. Translating Lisp to C++ by hand is probably pointless, since
> > compiling Lisp converts it to ASSEMBLER.
> >
> > What's left to do? (a) discover additional structure in your problem
> > that enables you to solve it. (b) choose a different problem :)
> >
> > RJF
> >
> >
> > ------------------------------
> > *From:* maxima-bounces at math.utexas.edu [mailto:
> > maxima-bounces at math.utexas.edu] *On Behalf Of *ahmet alper parker
> > *Sent:* Saturday, May 19, 2007 10:18 AM
> > *To:* maxima at math.utexas.edu
> > *Subject:* Re: [Maxima] ram problem
> >
> > Dear Richard,
> > I saw MMA at your web site. I want to inform you that I have downloaded
> > a copy of it. Can this be a solution to my problem? Also in future I may
> > have to solve more equations than the belows like 48 unknowns in a similar
> > formulation. In my university we have a supercomputer that can handle
> > parallel computations, can maxima or mma or other software (instead of the
> > commercial ones like mathematica, maple etc.) be compiled to do parallel
> > computation? I saw that lisp is the main programming language in this field.
> > If there is no parallel lisp compiler, is it possible to translate lisp code
> > to c++ or equivalent to parallelize it?
> > Thanks a lot all of you...
> > Ahmet Alper Parker
> >
> >
> > On 5/19/07, ahmet alper parker <aaparker at gmail.com> wrote:
> > >
> > > Dear Richard and Robert
> > > Thanks for the wise solution. I am sending you the command I have
> > > tried to solve. On cygwin I succesfully compiled maxima with clisp and it
> > > stoped because of the lack of memory I do not have instead of the programs
> > > own limitations. Here is the problem:
> > >
> > > ***************************************************************************************************************
> > > algsys([
> > > t/(4*A)*(b1^2*D11+a1^2*D33)=k11-k71^2/k77,
> > > t/(4*A)*(b1*b2*D11+a1*a2*D33)=k21-(k72*k71)/k77,
> > > t/(4*A)*(b2^2*D11+a2^2*D33)=k22-k72^2/k77,
> > > t/(4*A)*(b1*b3*D11+a1*a3*D33)=k31-(k71*k73)/k77,
> > > t/(4*A)*(b2*b3*D11+a2*a3*D33)=k32-(k72*k73)/k77,
> > > t/(4*A)*(b3^2*D11+a3^2*D33)=k33-k73^2/k77,
> > > t/(4*A)*(a1*b1*D12+a1*b1*D33)=k41-(k71*k74)/k77,
> > > t/(4*A)*(a1*b2*D12+a2*b1*D33)=k42-(k72*k74)/k77,
> > > t/(4*A)*(a1*b3*D12+a3*b1*D33)=k43-(k73*k74)/k77,
> > > t/(4*A)*(a1^2*D22+b1^2*D33)=k44-k74^2/k77,
> > > t/(4*A)*(a2*b1*D12+a1*b2*D33)=k51-(k71*k75)/k77,
> > > t/(4*A)*(a2*b2*D12+a2*b2*D33)=k52-(k72*k75)/k77,
> > > t/(4*A)*(a2*b3*D12+a3*b2*D33)=k53-(k73*k75)/k77,
> > > t/(4*A)*(a1*a2*D22+b1*b2*D33)=k54-(k74*k75)/k77,
> > > t/(4*A)*(a2^2*D22+b2^2*D33)=k55-k75^2/k77,
> > > t/(4*A)*(a3*b1*D12+b3*a1*D33)=k61-(k71*k76)/k77,
> > > t/(4*A)*(a3*b2*D12+b3*a2*D33)=k62-(k72*k76)/k77,
> > > t/(4*A)*(a3*b3*D12+b3*a3*D33)=k63-(k73*k76)/k77,
> > > t/(4*A)*(a1*a3*D22+b1*b3*D33)=k64-(k74*k76)/k77,
> > > t/(4*A)*(a2*a3*D22+b2*b3*D33)=k65-(k75*k76)/k77,
> > > t/(4*A)*(a3^2*D22+b3^2*D33)=k66-k76^2/k77,
> > > b3*k21-b2*k31+a3*k51-a2*k61=(-k71),
> > > b3*k22-b2*k32+a3*k52-a2*k62=(-k72),
> > > b3*k23-b2*k33+a3*k53-a2*k63=(-k73),
> > > b3*k24-b2*k34+a3*k54-a2*k64=(-k74),
> > > b3*k25-b2*k35+a3*k55-a2*k65=(-k75),
> > > b3*k26-b2*k36+a3*k56-a2*k66=(-k76),
> > > b3*k27-b2*k37+a3*k57-a2*k67=(-k77)
> > > ],[
> > >
> > > k11,k21,k22,k31,k32,k33,k41,k42,k43,k44,k51,k52,k53,k54,k55,k61,k62,k63,k64,k65,k66,k71,k72,k73,k74,k75,k76,k77
> > > ])
> > > ***************************************************************************************************************
> > >
> > > How should I approach the solution? What should I do in this case? If
> > > there is a reading about efficient computation of the same problem on
> > > maxima, can you drop a link?
> > > Thanks a lot :)
> > > Ahmet Alper Parker
> > >
> > >
> > > On 5/19/07, Robert Dodier <robert.dodier at gmail.com > wrote:
> > > >
> > > > On 5/19/07, Richard Fateman <fateman at cs.berkeley.edu> wrote:
> > > >
> > > > > Without further analysis, it is hard to know, but it may simply
> > > > be the case
> > > > > that having 2X or 4X the RAM available will not be enough
> > > > either. The wrong
> > > > > approach can put you on a path where the solution takes
> > > > exponential memory
> > > > > in the size of the input.
> > > >
> > > > Agreed 100% here. Just increasing the memory may very well
> > > > mean it just takes more time before running into the same error.
> > > >
> > > > It would help a lot to know more about the details of the problem.
> > > >
> > > > Robert
> > > >
> > >
> > >
> >
>