Re: [Maxima-discuss] What is slow about large expressions?

[Oscar B. <osc...@gm...>]

On Mon, 15 Jan 2024 at 16:18, Richard Fateman <fa...@gm...> wrote:
>
> I also find it unlikely that an error of this nature has been in Maxima since
> 1968 or so.
> RJF

I can reproduce it with 5.26.0 from 2011 (on sbcl):

$ git show
commit bb62396a9d252735031c3eeed12220daf7abaa61 (HEAD, tag: 5.26.0)
Author: Robert Dodier <rob...@us...>
Date:   Sat Dec 10 18:58:07 2011 -0700

    Put recently-created dqagp.lisp on list of SLATEC files.

diff --git a/src/Makefile.am b/src/Makefile.am
index 26b785a96..f94cf13ba 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -550,6 +550,7 @@ numerical/slatec/dqage.lisp \
 numerical/slatec/dqagie.lisp \
 numerical/slatec/dqagi.lisp \
 numerical/slatec/dqag.lisp \
+numerical/slatec/dqagp.lisp \
 numerical/slatec/dqagpe.lisp \
 numerical/slatec/dqagse.lisp \
 numerical/slatec/dqags.lisp \

$ ./maxima-local -b ../bug.mac
Maxima 5.26.0 http://maxima.sourceforge.net
using Lisp SBCL 2.1.11.debian
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1)                          batch(../bug.mac)

read and interpret file: /home/oscar/current/active/bug.mac
(%i2)                          display2d : false
(%i3) linel:125
(%i4) var1:z^2*z^2*s*z/l^4
(%i5) var2:(-r^z*o[z])/l^z
(%i6) var3:(-r^z*o[z]*z^2)/l^z
(%i7) var4:r^z/l^z
(%i8) var5:sqrt(var1)*o[z]*(r/l)^(z-2)
(%i9) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5)*o[z]/l^2
(%i10) var6:(-sqrt(var1)*r^z)/(z-2)
(%i11) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5)*o[z]/l^2
(%i12) diff_expr1:diff(var2,r)
(%i13) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5)*o[z]/l^2
(%i14) diff_expr2:diff(var3,r)
(%i15) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5)*o[z]/l^2
(%i16) diff_expr3:diff(var5,r)
(%i17) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5)*o[z]/l^2
(%i18) diff_expr4:var4*diff_expr2
(%i19) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5)*o[z]/l^2
(%i20) diff_expr5:var6*diff_expr3
(%i21) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5*o[z])*o[z]/l^2
(%i22) diff_expr6:diff_expr5+diff_expr4
(%i23) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5*o[z])*o[z]/l^2
(%i24) diff_expr:diff_expr1-diff_expr6
(%i25) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5*o[z])*o[z]/l^2
(%i26) check1:fullratsimp(diff_expr)
(%i27) print("HEY VAR5=",var5)
HEY VAR5= (r/l)^(z-2)*sqrt(s*z^5*o[z])*o[z]/l^2
(%o27) "/home/oscar/current/active/maxima.git/../bug.mac"

That is the oldest standard format release tag in the git repo but the
oldest commit is version 5.4 from 2000:

$ git log --reverse
commit 9e8326577594ad8d1b066e9ffcab7b5443b16b9e (tag: Version5_4)
Author: wfs <wfs>
Date:   Mon May 8 06:09:44 2000 +0000

    maxima-5.4 source as released nov 18 with maxima-5.4.tgz

I'm not sure how to build Maxima from such old commits though because
there's no configure/Makefile/README etc:

$ git checkout 9e8326577594ad8d1b066e9ffcab7b5443b16b9e
HEAD is now at 9e8326577 maxima-5.4 source as released nov 18 with
maxima-5.4.tgz
$ ls
archive  COPYING  COPYING1  demo  doc  interfaces  plotting  share  src  tests

--
Oscar