- GiNaC-list - ginac.de

same expression prints in differs orders
by Jose Antonio Garcia Peiro 21 Sep '10

21 Sep '10

>Hello, >On Tue, Sep 21, 2010 at 12:01 AM, Jose Antonio Garcia Peiro ><jgpeiro at gmail.com <https://www.cebix.net/mailman/listinfo/ginac-list>> wrote: >>* I think that the problem is at internal representation or at internal order. When*>>* I debug the code, same expression prints differ.*>>* ex test = pow(log(x),2)/x;*>>* cout << test;*>>* // sometimes x^(-1)*log(x)^2*>>* // other sometimes log(x)^2*x^(-1)* >Works as designed. This behavior is documented in the manual >(section 5.7.2, titled as 'Expanding and collecting'): "Again, >since the canonical form in GiNaC is not easy to guess you >should be prepared to see different orderings of terms in such >sums!". Also it has been explained on this mailing list several >(quite a number, actually) times, see e.g. > http://www.cebix.net/pipermail/ginac-list/2010-April/001598.html > h <http://www.ginac.de/pipermail/ginac-list/2008-August/001403.html>ttp://www.ginac.de/pipermail/ginac-list/2008-August/001403.html <http://www.ginac.de/pipermail/ginac-list/2008-August/001403.html> >>* How I can force GiNaC to unique representation?* >You can't. And there's no need to do so. Instead fix the (buggy) >code which makes assuptions about term ordering. >>* I am try to test expressions with "match", but it not works*>>* always with the same expression.* >Could you please post the actual expression and the pattern, >so I can make a (more) specific suggestion? >Best regards, > Alexei >You can't. And there's no need to do so. Instead fix the (buggy) >code which makes assuptions about term ordering. *mmm, I write about 50 lines with these assumptions, and i think that is not easy to correct....:-(* * * * >Could you please post the actual expression and the pattern, >so I can make a (more) specific suggestion? The code try to find the integral of a function. The code include all basic integration rules, for the function log(x)^2*x^(-1) apply these rule. ex f = pow(log(x),2)/x; // case a: f = x^(-1)*log(x)^2, case b: log(x)^2* x^(-1) * *ex w0, w1, w2;* *exmap m;* * * *if( f.match( pow(wild(0),wild(1))*wild(2), m ) || f.match( pow(wild(0),wild(1)), m ) ){ **// int( f^c*f', x) = f^(c+1)/(c+1) or ln(f) if c == -1* * w2 = 1; for( exmap::const_iterator i=m.begin(); i!=m.end(); ++i){ if (i->first.is_equal(wild(0)) ) w0 = i->second; // f else if (i->first.is_equal(wild(1)) ) w1 = i->second; // c else if (i->first.is_equal(wild(2)) ) w2 = i->second; // f' } if( has(w0,x) && !has(w1,x) ){ // f depends on x and c is constant ex dw0 = w0.diff(x,1); if( !dw0.is_equal(0) ){ // prevents division by 0 if( !has(w2/dw0,x) ){ if( w1.is_equal(-1) ){ //check if c == -1 return log( w0 ) * (w2/dw0); }else{ return pow( w0, w1+1 )/(w1+1) * (w2/dw0); } } } } } * * * *In case a: f = x, c = -1, and f' = log(x)^2, the code cannot compute the integral because f'/df = w2/dw0 = (log(x)^2)/(-x^-2) has the term 'x' and it cannot move out of integral.* *In case b: f = log(x), c = 2, f' = x^(-1), the code can compute integral because f'/df = w2/dw0 = x^(-1)/x^(-1) do not have the term 'x' and it can move out of integral.* The code fails because I assume that the product w2 dont have powers.

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same expression prints in differs orders
by Jose Antonio Garcia Peiro 21 Sep '10

21 Sep '10

Hi, I am try to test expressions with "match", but it not works always with the same expression. I think that the problem is at internal representation or at internal order. When I debug the code, same expression prints differ. ex test = pow(log(x),2)/x; cout << test; // sometimes x^(-1)*log(x)^2 // other sometimes log(x)^2*x^(-1) How I can force GiNaC to unique representation? thanks

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coeff() method
by Burcin Erocal 19 Sep '10

19 Sep '10

Hi, The following problem was reported to the Sage bug tracker by Paul Zimmermann: http://trac.sagemath.org/sage_trac/ticket/9505 ginsh - GiNaC Interactive Shell (ginac V1.5.7) <snip> Type ?? for a list of help topics. > f = x*y*z^2; y*z^2*x > coeff(f, z^2,1); y*x > coeff(f, x*y,1); 0 I'd greatly appreciate any help fixing this. Cheers, Burcin

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Fw: [sage-support] (5-e^x).substitute(x=log(x)) goes wrong?
by Burcin Erocal 19 Sep '10

19 Sep '10

Hi, This was reported to the sage-support list. I was intending to CC ginac-list in my reply, but hit send a bit too soon. Cheers, Burcin Begin forwarded message: On Fri, 10 Sep 2010 08:10:45 -0700 (PDT) KvS <keesvanschaik(a)gmail.com> wrote: > Dear all, > > I'm sorry I have yet again something to bother you with. Running the > following few lines: > > eq=5-e^x > print "1:",eq.substitute(x=3*x) > print "2:",eq.substitute(x=log(x)) > > yields the output (Sage 4.5.2 with Ubuntu): > > 1: -e^(3*x) + 5 > 2: -log(x) + 5 > > So 1 is fine, but it seems that to get to 2 Sage actually substitutes > twice no: 5-e^x -> 5-x -> 5-log(x). I had expected it would just give > me 5-x rather, is it a bug or a feature? Thanks for reporting the problem. This looks like a bug in GiNaC, the library we use for the symbolic expressions. ginsh - GiNaC Interactive Shell (ginac V1.5.7) __, _______ Copyright (C) 1999-2010 Johannes Gutenberg University Mainz, (__) * | Germany. This is free software with ABSOLUTELY NO WARRANTY. ._) i N a C | You are welcome to redistribute it under certain conditions. <-------------' For details type `warranty;'. Type ?? for a list of help topics. > subs(5-exp(x),x==log(x)); 5-log(x) I opened a ticket for this: http://trac.sagemath.org/sage_trac/ticket/9891

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using an "undefined" function
by Jose Antonio Garcia Peiro 09 Sep '10

09 Sep '10

Hi, I try to use an undefined function, such as f(x), instead of f(x)=3*x+... I know that the function depends on variable x, but not in what form. With SymbolicC++, if I define Symbolic x("x"), f[x] and g[x], the operation diff( f+g ,x ) returns diff(f,x)+diff(g,x). (the differentiation rule of sum operator) It is possible to make this with GiNaC? Thanks

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Crash Ginsh when trying to solve equation involving integral numerically
by Ernst Moritz Hahn 31 Aug '10

31 Aug '10

Hi, I tried to solve an equation numerically, using Ginsh from the git repository. When entering fsolve((1/(sqrt(2*Pi)))*integral(t,0,x,exp(-1/2*t^2))==0.5,x,0,100) into Ginsh, it crashes, see below. I got the same problem with the version shipped with the latest stable Ubuntu Linux. GCC version is "gcc (Ubuntu 4.4.3-4ubuntu5) 4.4.3". If you need more information, please tell me. Regards, Moritz emh@mate:~/ginac$ ./ginsh/ginsh ginsh - GiNaC Interactive Shell (ginac V1.5.0) __, _______ Copyright (C) 1999-2010 Johannes Gutenberg University Mainz, (__) * | Germany. This is free software with ABSOLUTELY NO WARRANTY. ._) i N a C | You are welcome to redistribute it under certain conditions. <-------------' For details type `warranty;'. Type ?? for a list of help topics. > fsolve((1/(sqrt(2*Pi)))*integral(t,0,x,exp(-1/2*t^2))==0.5,x,0,100); *** glibc detected *** /home/emh/ginac/ginsh/.libs/lt-ginsh: malloc(): memory corruption (fast): 0x091c7cdf *** ======= Backtrace: ========= /lib/tls/i686/cmov/libc.so.6(+0x6b591)[0x7b3591] /lib/tls/i686/cmov/libc.so.6(+0x6e710)[0x7b6710] /lib/tls/i686/cmov/libc.so.6(__libc_malloc+0x5c)[0x7b7f9c] /usr/lib/libstdc++.so.6(_Znwj+0x27)[0x70fc07] /home/emh/ginac/ginac/.libs/libginac-1.5.so.0(_ZNSt6vectorIN5GiNaC6expairESaIS1_EE7reserveEj+0x62)[0x3d4522] /home/emh/ginac/ginac/.libs/libginac-1.5.so.0(_ZNK5GiNaC9expairseq12subschildrenERKSt3mapINS_2exES2_NS_10ex_is_lessESaISt4pairIKS2_S2_EEEj+0x145)[0x414745] /home/emh/ginac/ginac/.libs/libginac-1.5.so.0(_ZNK5GiNaC9expairseq4subsERKSt3mapINS_2exES2_NS_10ex_is_lessESaISt4pairIKS2_S2_EEEj+0x37)[0x417347] /home/emh/ginac/ginsh/.libs/lt-ginsh(_ZNK5GiNaC9containerISt6vectorE12subschildrenERKSt3mapINS_2exES4_NS_10ex_is_lessESaISt4pairIKS4_S4_EEEj+0x65)[0x8062375] /home/emh/ginac/ginsh/.libs/lt-ginsh(_ZNK5GiNaC9containerISt6vectorE4subsERKSt3mapINS_2exES4_NS_10ex_is_lessESaISt4pairIKS4_S4_EEEj+0x2c)[0x80625fc] /home/emh/ginac/ginac/.libs/libginac-1.5.so.0(_ZNK5GiNaC9expairseq12subschildrenERKSt3mapINS_2exES2_NS_10ex_is_lessESaISt4pairIKS2_S2_EEEj+0x25c)[0x41485c] /home/emh/ginac/ginac/.libs/libginac-1.5.so.0(_ZNK5GiNaC9expairseq4subsERKSt3mapINS_2exES2_NS_10ex_is_lessESaISt4pairIKS2_S2_EEEj+0x37)[0x417347] /home/emh/ginac/ginac/.libs/libginac-1.5.so.0(_ZNK5GiNaC2ex4subsERKS0_j +0x1e0)[0x40eeb0] /home/emh/ginac/ginac/.libs/libginac-1.5.so.0(_ZN5GiNaC6fsolveERKNS_2exERKNS_6symbolERKNS_7numericES8_+0x1bfd)[0x47262d] /home/emh/ginac/ginsh/.libs/lt-ginsh[0x8059103] /home/emh/ginac/ginsh/.libs/lt-ginsh[0x805b52e] /home/emh/ginac/ginsh/.libs/lt-ginsh[0x805d64f] /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe6)[0x75ebd6] /home/emh/ginac/ginsh/.libs/lt-ginsh[0x8052ee1] ======= Memory map: ======== 00110000-00144000 r-xp 00000000 08:01 2359427 /lib/libncurses.so.5.7 00144000-00145000 ---p 00034000 08:01 2359427 /lib/libncurses.so.5.7 00145000-00147000 r--p 00034000 08:01 2359427 /lib/libncurses.so.5.7 00147000-00148000 rw-p 00036000 08:01 2359427 /lib/libncurses.so.5.7 00148000-002ca000 r-xp 00000000 08:01 2930970 /usr/lib/libcln.so.6.0.1 002ca000-002cc000 r--p 00182000 08:01 2930970 /usr/lib/libcln.so.6.0.1 002cc000-002d2000 rw-p 00184000 08:01 2930970 /usr/lib/libcln.so.6.0.1 002d2000-002d4000 rw-p 00000000 00:00 0 002d4000-002f1000 r-xp 00000000 08:01 2359423 /lib/libgcc_s.so.1 002f1000-002f2000 r--p 0001c000 08:01 2359423 /lib/libgcc_s.so.1 002f2000-002f3000 rw-p 0001d000 08:01 2359423 /lib/libgcc_s.so.1 002f3000-002f5000 r-xp 00000000 08:01 2363303 /lib/tls/i686/cmov/libdl-2.11.1.so 002f5000-002f6000 r--p 00001000 08:01 2363303 /lib/tls/i686/cmov/libdl-2.11.1.so 002f6000-002f7000 rw-p 00002000 08:01 2363303 /lib/tls/i686/cmov/libdl-2.11.1.so 00365000-00649000 r-xp 00000000 08:01 1250386 /home/emh/ginac/ginac/.libs/libginac-1.5.so.0.0.0 00649000-0064f000 r--p 002e3000 08:01 1250386 /home/emh/ginac/ginac/.libs/libginac-1.5.so.0.0.0 0064f000-00651000 rw-p 002e9000 08:01 1250386 /home/emh/ginac/ginac/.libs/libginac-1.5.so.0.0.0 00651000-00652000 rw-p 00000000 00:00 0 00652000-0073b000 r-xp 00000000 08:01 2885327 /usr/lib/libstdc ++.so.6.0.13 0073b000-0073c000 ---p 000e9000 08:01 2885327 /usr/lib/libstdc ++.so.6.0.13 0073c000-00740000 r--p 000e9000 08:01 2885327 /usr/lib/libstdc ++.so.6.0.13 00740000-00741000 rw-p 000ed000 08:01 2885327 /usr/lib/libstdc ++.so.6.0.13 00741000-00748000 rw-p 00000000 00:00 0 00748000-0089b000 r-xp 00000000 08:01 2363300 /lib/tls/i686/cmov/libc-2.11.1.so 0089b000-0089c000 ---p 00153000 08:01 2363300 /lib/tls/i686/cmov/libc-2.11.1.so 0089c000-0089e000 r--p 00153000 08:01 2363300 /lib/tls/i686/cmov/libc-2.11.1.so 0089e000-0089f000 rw-p 00155000 08:01 2363300 /lib/tls/i686/cmov/libc-2.11.1.so 0089f000-008a2000 rw-p 00000000 00:00 0 008c5000-00924000 r-xp 00000000 08:01 2915588 /usr/lib/libgmp.so.3.5.2 00924000-00925000 r--p 0005e000 08:01 2915588 /usr/lib/libgmp.so.3.5.2 00925000-00926000 rw-p 0005f000 08:01 2915588 /usr/lib/libgmp.so.3.5.2 009e8000-00a03000 r-xp 00000000 08:01 2359473 /lib/ld-2.11.1.so 00a03000-00a04000 r--p 0001a000 08:01 2359473 /lib/ld-2.11.1.so 00a04000-00a05000 rw-p 0001b000 08:01 2359473 /lib/ld-2.11.1.so 00a1c000-00a40000 r-xp 00000000 08:01 2363304 /lib/tls/i686/cmov/libm-2.11.1.so 00a40000-00a41000 r--p 00023000 08:01 2363304 /lib/tls/i686/cmov/libm-2.11.1.so 00a41000-00a42000 rw-p 00024000 08:01 2363304 /lib/tls/i686/cmov/libm-2.11.1.so 00c1d000-00c1e000 r-xp 00000000 00:00 0 [vdso] 00c66000-00c95000 r-xp 00000000 08:01 2359739 /lib/libreadline.so.6.1 00c95000-00c96000 r--p 0002e000 08:01 2359739 /lib/libreadline.so.6.1 00c96000-00c99000 rw-p 0002f000 08:01 2359739 /lib/libreadline.so.6.1 00c99000-00c9a000 rw-p 00000000 00:00 0 08048000-0806f000 r-xp 00000000 08:01 1250662 /home/emh/ginac/ginsh/.libs/lt-ginsh 0806f000-08070000 r--p 00026000 08:01 1250662 /home/emh/ginac/ginsh/.libs/lt-ginsh 08070000-08071000 rw-p 00027000 08:01 1250662 /home/emh/ginac/ginsh/.libs/lt-ginsh 08071000-08072000 rw-p 00000000 00:00 0 09197000-091d9000 rw-p 00000000 00:00 0 [heap] b7600000-b7621000 rw-p 00000000 00:00 0 b7621000-b7700000 ---p 00000000 00:00 0 b77cb000-b780a000 r--p 00000000 08:01 2889421 /usr/lib/locale/en_US.utf8/LC_CTYPE b780a000-b780e000 rw-p 00000000 00:00 0 b7825000-b782c000 r--s 00000000 08:01 2960058 /usr/lib/gconv/gconv-modules.cache b782c000-b782f000 rw-p 00000000 00:00 0 bff86000-bff9b000 rw-p 00000000 00:00 0 [stack] Aborted

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multithreading
by Kraus Philipp 23 Aug '10

23 Aug '10

Hello, I have declared a GiNaC::parser l_parser; in a class method which is called in a multithread. If I show valgrind report I see: ==1084== Possible data race during write of size 1 at 0x1f06e4 by thread #3 ==1084== at 0x1B30F6: std::string::_Rep::_M_set_length_and_sharable(unsigned long) (in /usr/ lib/libstdc++.6.0.4.dylib) ==1084== by 0x1B39FB: std::string::_M_mutate(unsigned long, unsigned long, unsigned long) (in /usr/lib/libstdc++.6.0.4.dylib) ==1084== by 0x1B3A43: std::string::_M_replace_safe(unsigned long, unsigned long, char const*, unsigned long) (in /usr/lib/libstdc++. 6.0.4.dylib) ==1084== by 0x1B3AE7: std::string::assign(char const*, unsigned long) (in /usr/lib/libstdc++.6.0.4.dylib) ==1084== by 0x115D139: GiNaC::lexer::lexer(std::istream*, std::ostream*, std::ostream*) (in /Developer/opt/Ginac/1.5.8/lib/ libginac-1.5.0.dylib) ==1084== by 0x1157CC2: GiNaC::parser::parser(std::map<std::string, GiNaC::ex, std::less<std::string>, std::allocator<std::pair<std::string const, GiNaC::ex> > > const&, bool, std::map<std::pair<std::string, unsigned long>, GiNaC::ex (*) (std::vector<GiNaC::ex, std::allocator<GiNaC::ex> > const&), std::less<std::pair<std::string, unsigned long> >, std::allocator<std::pair<std::pair<std::string, unsigned long> const, GiNaC::ex (*)(std::vector<GiNaC::ex, std::allocator<GiNaC::ex> > const&)> > > const&) (in /Developer/opt/Ginac/1.5.8/lib/ libginac-1.5.0.dylib) When will be ginac thread safe and is there such a thing? Thx Phil

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symtab problem with multithread
by Kraus Philipp 21 Aug '10

21 Aug '10

Hi, I try to use a GiNaC::symtab in a thread object. I copy a const reference to the threaded method and get problems on reading the symbols. If I take a symbol from the table with GiNaC::ex x = m_symbols["mysymbol"], I would run on > 1 thread into errors. Valgrind shows this information: Possible data race during write of size 4 at 0x1ea5c04 by thread #1 ==38631== at 0x8137: std::_Rb_tree<std::string, std::pair<std::string const, GiNaC::ex>, std::_Select1st<std::pair<std::string const, GiNaC::ex> >, std::less<std::string>, std::allocator<std::pair<std::string const, GiNaC::ex> > >::_M_erase(std::_Rb_tree_node<std::pair<std::string const, GiNaC::ex> >*) (in main) ==38631== by 0x92BF: boost::_bi::storage1<boost::_bi::value<worker<double, 2ul> > >::~storage1() (in main) ==38631== by 0xE0B0: boost::thread* boost::thread_group::create_thread<boost::_bi::bind_t<void, boost::_mfi::mf0<void, worker<double, 2ul> >, boost::_bi::list1<boost::_bi::value<worker<double, 2ul> > > > >(boost::_bi::bind_t<void, boost::_mfi::mf0<void, worker<double, 2ul> >, boost::_bi::list1<boost::_bi::value<mworker<double, 2ul> > > >) (in main) I have copied the table with std::copy( p_syms.begin(), p_syms.end(), std::inserter(m_symbols, m_symbols.begin())); p_syms is the original table and m_symbols should be the copy, but it doesn't work. In my thread object I can use a deep copy of the symbol table, because every thread is independed of the other threads. I'm not sure that the problem is a GiNaC problem, but you can give some tips perhaps. Thanks Phil

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ginsh: valgrind reports 26 bytes lost
by Joerg Arndt 17 Aug '10

17 Aug '10

While we are at it: % valgrind --leak-check=full ginsh ==5463== Memcheck, a memory error detector ==5463== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al. ==5463== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info ==5463== Command: ginsh ==5463== ginsh - GiNaC Interactive Shell (ginac V1.5.8) __, _______ Copyright (C) 1999-2010 Johannes Gutenberg University Mainz, (__) * | Germany. This is free software with ABSOLUTELY NO WARRANTY. ._) i N a C | You are welcome to redistribute it under certain conditions. <-------------' For details type `warranty;'. Type ?? for a list of help topics. > [pressing ctrl-d to exit] ==5463== ==5463== HEAP SUMMARY: ==5463== in use at exit: 743,496 bytes in 486 blocks ==5463== total heap usage: 3,081 allocs, 2,595 frees, 980,701 bytes allocated ==5463== ==5463== 26 bytes in 1 blocks are definitely lost in loss record 15 of 55 ==5463== at 0x4C26C3A: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==5463== by 0x59FEEA2: cln::xmalloc(unsigned long) (cl_malloc.cc:28) ==5463== by 0x5A077DD: cln::cl_make_heap_string(char const*) (cl_st_make1.cc:20) ==5463== by 0x5A05866: cln::cl_prin_globals_init_helper::cl_prin_globals_init_helper() (string.h:83) ==5463== by 0x5B27C05: global constructors keyed to cl_SV_number_aprint.cc (io.h:78) ==5463== by 0x5B27C65: ??? (in /usr/local/lib/libcln.so.6.0.1) ==5463== by 0x59FAF8A: ??? (in /usr/local/lib/libcln.so.6.0.1) ==5463== ==5463== LEAK SUMMARY: ==5463== definitely lost: 26 bytes in 1 blocks ==5463== indirectly lost: 0 bytes in 0 blocks ==5463== possibly lost: 0 bytes in 0 blocks ==5463== still reachable: 743,470 bytes in 485 blocks ==5463== suppressed: 0 bytes in 0 blocks ==5463== Reachable blocks (those to which a pointer was found) are not shown. ==5463== To see them, rerun with: --leak-check=full --show-reachable=yes ==5463== ==5463== For counts of detected and suppressed errors, rerun with: -v ==5463== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 2 from 2)

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remove entry from symtab
by Kraus Philipp 16 Aug '10

16 Aug '10

Hi, I'm using GiNaC 1.5.8 and have declared a GiNaC::symtab with symbols. How can I remove a symbole (by string name or GiNaC::symbol expression) from the table? I don't find anything about the symtab in the documentation Thanks Phil

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