The changes proposed in that article were not put in to Maxima
by me. I doubt that Bill Schelter or anyone else has done
this.
A change of this nature would have to be tested very
carefully to make sure it did not break any other programs.
As you know, the programming of Macsyma has not always
been very "disciplined".
I believe the benchmark code would run without change
in the current Maxima.
RJF
Andrei Zorine wrote:
> Hello,
> I tried one of the tests proposed by Prof. Fateman in 'Speeding up
> Lisp-based Symbolic Mahematics' - computing sum(a[i],i,1,N) for
> different values of N. The timings on my PII-233 PC are ([N,time])
> [[100, 0.17],
> [200, 0.43],
> [300, 1.87],
> [400, 2.53],
> [500, 3.45],
> [600, 4.82],
> [700, 6.58],
> [1000, 14.1],
> [1200, 22.02],
> [1500, 32.18],
> [2000, 64.37],
> [2200, 83.27]],
>
> I think it's still O(n^2). build_info() is
>
> Maxima version: 5.9.0
> Maxima build date: 19:10 2/9/2003
> host type: i686-pc-mingw32
> lisp-implementation-type: Kyoto Common Lisp
> lisp-implementation-version: GCL-2-5.0
>
> Then I tried a[i]=f(a[i-1]) stuff, literally
> (C39) a[0]:x$
> (C40) for i:1 thru 3000 do a[i]:f(a[i-1])$
> and got
>
> (C41) a[345]
> ;
>
> Evaluation took 0.00 seconds (0.00 elapsed)
> (D41)
>
> f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f
>
>
> (f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f
>
>
>
> Error: Bind stack overflow.
> Fast links are on: do (si::use-fast-links nil) for debugging
> Error signalled by CATCH.
> Broken at MACSYMA-TOP-LEVEL. Type :H for Help.
> MAXIMA>>:q
>
> Computing sum(a[i],i,1,2200)$ didn't stop in few minutes.
>
> So, my question is: are the changes proposed in the above article
> added to the current Maxima?
> --
> Andrei Zorine
>
>
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