Open rtoy opened 2 months ago
Imported from SourceForge on 2024-07-06 10:02:36 Created by robert_dodier on 2022-01-31 01:35:10 Original: https://sourceforge.net/p/maxima/bugs/3933/#3753
Ticket moved from /p/maxima/feature-requests/161/
Imported from SourceForge on 2024-07-06 10:02:39 Created by robert_dodier on 2022-01-31 02:00:40 Original: https://sourceforge.net/p/maxima/bugs/3933/#feab
Guillermo, thanks for the bug report.
My first guess about what's going on is that you are constructing extremely huge expressions in cspline
and then trying to do some operations on those which make them even more enormous, and eventually Maxima runs out of memory.
If you attach the data file or files to this bug report, it would help others understand what's going on.
It would also help othes understand if you explain something about what you are trying to do. What is the larger goal you are working towards?
Imported from SourceForge on 2024-07-06 10:02:43 Created by guillepo on 2022-01-31 11:51:58 Original: https://sourceforge.net/p/maxima/bugs/3933/#6501
Hello Robert, I have set dynamalloc to true and a lot enough of ram memory, the maxima process in question only take a half of it, but thinking about your comment I change to a non interpolating version of my code. One issue that I am not sure is how to manage the sqrt redefinition to mysqrt. It is needed because the default definition of the branch cut selected by maxima but not adjustable by user, is not it? As a mathematical task, briefly I want to solve a 4x4 linear eq. system from there I obtain an expression depending on several parameters and two variables (q,k) and then from here I want to obtain a couple of expression that I made as list and then deliver into two output files. Regards
Imported from SourceForge on 2024-07-06 10:02:46 Created by macrakis on 2022-01-31 14:33:59 Original: https://sourceforge.net/p/maxima/bugs/3933/#5c00
Imported from SourceForge on 2024-07-06 10:02:50 Created by macrakis on 2022-01-31 14:37:43 Original: https://sourceforge.net/p/maxima/bugs/3933/#868e
Why are you constructing these huge expressions with lots and lots of common subexpressions?
Even the very naive optimize
function reduces your epsM
from 37k characters to 2650 characters (in string
form).
Imported from SourceForge on 2024-07-06 10:02:53 Created by guillepo on 2022-01-31 14:54:54 Original: https://sourceforge.net/p/maxima/bugs/3933/#b285
Hello Stavros, I think that main problem is with mysqrt definition. I have not found any other form to manage the selection of other branch cut for sqrt function defined by Maxima. I am trying a code version without cspline and seems after 3 hs with core i7 7ma generation processor and 16 GB RAM , that Maxima using 8GB is working to hard to manage it I will kill it and I could try with optimize before, thank you in advance Regards
Imported from SourceForge on 2024-07-06 10:02:57 Created by macrakis on 2022-01-31 15:01:03 Original: https://sourceforge.net/p/maxima/bugs/3933/#b285/2eea
I can't execute your code beyond the definition of epsM
(because of the file load), so I'm not sure what it's doing. But if the goal is numerical (not symbolic) calculation, it is probably unnecessary to carry around those huge symbolic expressions.
A common error in using Maxima is to generate large symbolic expressions which are later evaluated for specific numbers. It is often better just to do the numerical calculation. This is especially true for interpolation.
Imported from SourceForge on 2024-07-06 10:03:00 Created by guillepo on 2022-01-31 15:09:38 Original: https://sourceforge.net/p/maxima/bugs/3933/#3743
OK, let me share a code version similar to the above but without cspline. I am totally agree with you about numerical versus symbolic, the problem for me is I am not how to manage the sqrt redefinition according to the neeede branch cut that I said before.
dynamalloc:true;
eq1:ED1*exp(%i*k1*d1)-ED2*exp(%i*k2*d1)+EI1*exp(-%i*k1*d1)-EI2*exp(-%i*k2*d1)=DE0*exp(%i*k*d1);
eq2:k1*ED1*exp(%i*k1*d1)-k2*ED2*exp(%i*k2*d1)-k1*EI1*exp(-%i*k1*d1)+k2*EI2*exp(-%i*k2*d1)=k*DE0*exp(%i*k*d1);
eq3:ED1-ED2*exp(%i*(k2-k)*d)+EI1-EI2*exp(-%i*(k2+k)*d)=DE0;
eq4:k1*ED1-k2*ED2*exp(%i*(k2-k)*d)-k1*EI1+k2*EI2*exp(-%i*(k2+k)*d)=k*DE0;
neq:linsolve([eq1,eq2,eq3,eq4],[ED1,ED2,EI1,EI2]);
E01:4*%pi*q*J0/(%i*c**2*(k1**2-k**2));
E02:4*%pi*q*J0/(%i*c**2*(k2**2-k**2));
neq:subst(DE0=E02-E01,neq);
[ED1,ED2,EI1,EI2]:subst(neq,[ED1,ED2,EI1,EI2]);
sinc(x):=sin(x)/x;
epsM:(k/q)**2*c**2+4*%pi*J0*d/(%i*q*(d1*E01+d2*E02+
ED1*d1*sinc((k1-k)*d1/2)*exp(%i*(k1-k)*d1/2)+
EI1*d1*sinc((k1+k)*d1/2)*exp(-%i*(k1+k)*d1/2)+
ED2*d2*sinc((k2-k)*d2/2)*exp(%i*(k2-k)*d2/2)+
EI2*d2*sinc((k2+k)*d2/2)*exp(-%i*(k2+k)*d2/2)));
epsM(z):=subst(k=z,epsM);
epsMD2:at(diff(epsM(z),z,2),z=0.001);
mysqrt(x):= if imagpart(sqrt(x))<0 then -sqrt(x) else sqrt(x);
#mysqrt(x):= sqrt(x);
epsM:subst([k1=mysqrt(e1)*q/c,k2=mysqrt(e2)*q/c,d1=80.0,d2=20.0,d=100.0,J0=1.0],epsM(0.001));
eps2:1.0-1.0/(q**2+%i*q*0.01);
eps1:(1.645+5.0732*10**3*q**2/(2*%pi*c)**2 + 2.31*10**7*q**4/(2*%pi*c)**4)**2;
epsM:subst([e1=eps1,e2=eps2,c=197.33],epsM);
epsM1(x):=subst(q=x,epsM);
epsM2re(x):=float(realpart(epsM1(x)));
epsM2im(x):=float(imagpart(epsM1(x)));
epsMlist:makelist([i,epsM2re(i),epsM2im(i)],i,1.5,3.5,0.04);
epsOut:openw("epsMwithoutInt.dat");
write_data(epsMlist,epsOut);
close(epsOut);
Imported from SourceForge on 2024-07-06 10:03:04 Created by peterpall on 2022-01-31 15:16:19 Original: https://sourceforge.net/p/maxima/bugs/3933/#f1ad
I once had a calculation that if done with floats suffered from the problem that adding a small float to a big one doesn't change the big float. Redoing the calculation with exact numbers exceeded the amount of memory gcl can allocate. But a maxima that was compiled with clips did the trick - even if it took about 8 hours.
Imported from SourceForge on 2024-07-06 10:03:07 Created by dauti on 2022-01-31 15:18:05 Original: https://sourceforge.net/p/maxima/bugs/3933/#741c
If I remember correctly, the Maxima startscript ($INSTALLPREFIX/bin/maxima
or src/maxima.in
in the Maxima sourcecode) limits GCL memory consumption; see commit https://sourceforge.net/p/maxima/code/ci/9e712a93
You can try to increase/remove this limit.
Imported from SourceForge on 2024-07-06 10:02:35 Created by guillepo on 2022-01-29 15:57:23 Original: https://sourceforge.net/p/maxima/bugs/3933
Dear Maxima Team, I am not sure about this issue, but I did not found it in any blog or mailing list. According to this report a related lisp error with MACSYMA TOP LEVEL memory in CONS expression is the cause.
++++++++ here the output message:
Maxima encountered a Lisp error:
Condition in MACSYMA-TOP-LEVEL [or a callee]: INTERNAL-SIMPLE-ERROR: The storage for CONS is exhausted. 1634280 pages allocated. Use ALLOCATE to expand the space.
Automatically continuing. +++++++
and here the bug_report() output:
Please report bugs to: https://sourceforge.net/p/maxima/bugs To report a bug, you must have a Sourceforge account. Please include the following information with your bug report:
Maxima version: "5.44.0" Maxima build date: "2021-04-24 14:52:58" Host type: "x86_64-pc-linux-gnu" Lisp implementation type: "GNU Common Lisp (GCL)" Lisp implementation version: "GCL 2.6.12" User dir: "/home/gortiz/.maxima" Temp dir: "/tmp" Object dir: "/home/gortiz/.maxima/binary/5_44_0/gcl/GCL_2_6_12" Frontend: false
Below I copy the code, but to run a couple of tables are required and many pages are displayed. Please, let me know is it is needed anyway. They are interpolated after makelist for eack are doing. Also I introduce my own sqrt (mysqrt) because I need a different branch cut by default in maxima.
thank you in advance for your attention Regards
´´´