I sent my friend your answer about  enlarging the stack size, that stack size nor mally isn't the problem, that the problem is often elsewhere.

He sent me this.

Tom,

I ran the program for some hours and made some test output. The program does not hang but proceeds very slowly because the expressions to be calculated/simplified are really huge. I use the combination for simplifying:

 

trigsimp(factor(ratsimp(f)))

 

Mainly there are 2 repeated error messages:

 

Maxima encountered a Lisp error:

 

 Error in MACSYMA-TOP-LEVEL [or a callee]: The storage for STREAM is exhausted.

Currently, 222 pages are allocated.

Use ALLOCATE to expand the space.

 

 

Maxima encountered a Lisp error:

 

 Error in PROGN [or a callee]: The storage for CONS is exhausted.

Currently, 16881 pages are allocated.

Use ALLOCATE to expand the space.

 

 

The version I use is

-------------------------------------------------------------

Maxima version: 5.16.3

Maxima build date: 22:48 8/24/2008

host type: i686-pc-mingw32

lisp-implementation-type: GNU Common Lisp (GCL)

lisp-implementation-version: GCL 2.6.8

 

I've asked him to isolate the code (20-40 line) causing his problem. He said it would try to do that but it would be easy.

Do these messages give us any clue as to what to look for?

Tom Widlar.

From: Stavros Macrakis <macrakis <at> alum.mit.edu>

The symptom you describe, running for a long time (perhaps an infinite time?), is not a symptom of a stack overflow, so increasing the size of the stack won't help.

It could be that the calculation is intrinsically computationally expensive, or that the algorithm being used is not efficient, or that the algorithm is incorrect and is in an infinite loop, or that there is a gross inefficiency or bug in some Maxima routine. There is no way to know without actually seeing the problem.

Without enough information to reproduce the problem, it is very hard to give any useful advice. It often turns out that the problem is not at all what the user thinks it is.  A good problem report includes the following information:

• A clear procedure for reproducing the problem. Please verify that your procedure actually re-creates the problem in a fresh Maxima. If you can't reproduce it, still send it along, but try to include as much information about what you did before. The simpler and shorter the procedure, the better. It's always appreciated when the discoverer of a bug narrows it down to a simple case. Differentials are always good, too -- that is, cases which are almost the same but DO work.

• The exact version number you're running under, as shown by bug_report().

In particular, the type of Lisp being used is very important for some issues (e.g. behavior on stack overflow), but the CPU speed and memory size are not usually relevant.

             -s

On Sun, Aug 31, 2008 at 5:26 PM, Thomas Widlar <twidlar <at> yahoo.com> wrote:

A friend of mine asked this question.

 If I remember right, the stack size is fixed and determined by the Lisp subsystem. I have the problem that I cannot compute some complicated metrics because Maxima hangs and eats up 99% of CPU time. Probably the stack size is exhausted. Is a way to increase the stack? Maybe by recompilation with a higher stack size?

His setup is

  Maxima 5.16.3, Windows distribution
  running on Windows XP, SP 3
  CPU: Pentium 4, 2.66 GHz  
  Memory: 1 GB

 

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