- GiNaC-devel - ginac.de

Expand method in functions
by Vladimir V. Kisil 31 Jul '13

31 Jul '13

Dear All, So far we had pow(2,a+b).expand() -> pow(2,a)*pow(2,b), but exp(a+b).expand() -> exp(a+b). It will be also nice to have abs(a*b).expand() -> abs(a)*abs(b) and log(a*b).expand() -> log(a) + log(b) (for positive a and b, of course). Thus, I am proposing a patch for this. Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv(a)maths.leeds.ac.uk www: http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://www.worldscientific.com/worldscibooks/10.1142/p835

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Some more evaluation rules for abs()
by Vladimir V. Kisil 31 Jul '13

31 Jul '13

Dear All, I have added some more evaluation rules for abs(). They evaluate absolute values of powers and exponents. Simple checks are added as well. The effect is like this: realsymbol a("a"), b("b"), x("x"), y("y"); cout << abs(exp(x+I*y)).eval() << endl; // before: -> abs(exp(x+I*y)) // now: -> exp(x) cout << abs(pow(x+I*y,a+I*b)).eval() << endl; // before: -> abs((x+I*y)^(I*b+a)) // now: -> abs(x+I*y)^a Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv(a)maths.leeds.ac.uk www: http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://www.worldscientific.com/worldscibooks/10.1142/p835

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Re: [GiNaC-devel] Build issues (Was: Simplifying powers)
by Vladimir V. Kisil 31 Jul '13

31 Jul '13

Dear Alexei, >>>>> On Wed, 31 Jul 2013 11:24:51 +0300, Alexei Sheplyakov <alexei.sheplyakov(a)gmail.com> said: ASh> It looks like bison is missing (the configure script should ASh> have printed the corresponding warning). Could you please send ASh> your config.log file? Bison is present, as far as I can see. So, I am attaching the config.log and giving the output of autoreconf below. Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv(a)maths.leeds.ac.uk www: http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://www.worldscientific.com/worldscibooks/10.1142/p835 ================================================================= libtoolize: putting auxiliary files in AC_CONFIG_AUX_DIR, `config'. libtoolize: copying file `config/ltmain.sh' libtoolize: putting macros in AC_CONFIG_MACRO_DIR, `m4'. libtoolize: copying file `m4/libtool.m4' libtoolize: copying file `m4/ltoptions.m4' libtoolize: copying file `m4/ltsugar.m4' libtoolize: copying file `m4/ltversion.m4' libtoolize: copying file `m4/lt~obsolete.m4' configure.ac:31: installing 'config/config.guess' configure.ac:31: installing 'config/config.sub' configure.ac:21: installing 'config/install-sh' configure.ac:21: installing 'config/missing' check/Makefile.am: installing 'config/depcomp' parallel-tests: installing 'config/test-driver' doc/examples/Makefile.am:8: installing 'config/texinfo.tex' doc/tutorial/Makefile.am:4: installing 'config/mdate-sh' ginsh/Makefile.am:7: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS') configure.ac: installing 'config/ylwrap'

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[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-385-gca11a8c
by git＠ginac.de 30 Jul '13

30 Jul '13

This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "GiNaC -- a C++ library for symbolic computations". The branch, master has been updated via ca11a8c1471ae650f0124db5e9bf48cc04f9d8f0 (commit) via b23a2dfdcd478b00a11c6c2184fbe197a3ac5bfb (commit) from e45f9fca76b81e01ffa5edc417c29538fa05147b (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit ca11a8c1471ae650f0124db5e9bf48cc04f9d8f0 Author: Vladimir V. Kisil <kisilv(a)maths.leeds.ac.uk> Date: Sun Jul 28 23:25:01 2013 +0100 Add the case of c1=-1 and c2>0 to the rewriting rule of exponents: (x^c1)^c2 -> x^(c1 * c2) commit b23a2dfdcd478b00a11c6c2184fbe197a3ac5bfb Author: Alexei Sheplyakov <Alexei.Sheplyakov(a)gmail.com> Date: Sun Jul 28 18:43:06 2013 +0300 [bugfix] factor_univariate(): handle polinomials over rationals (no segfaults any more). ----------------------------------------------------------------------- Summary of changes: check/CMakeLists.txt | 1 + check/Makefile.am | 4 ++++ check/exam_powerlaws.cpp | 6 +++--- check/factor_univariate_bug.cpp | 21 +++++++++++++++++++++ ginac/factor.cpp | 12 +++++++++++- ginac/power.cpp | 7 ++++--- 6 files changed, 44 insertions(+), 7 deletions(-) create mode 100644 check/factor_univariate_bug.cpp hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

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Housekeeping work in inifcns.cpp
by Vladimir V. Kisil 30 Jul '13

30 Jul '13

Dear All, I made a bit of housekeeping work in inifcns.cpp: 1) Make abs_power aware on even powers, even if they are not numeric. 2) Add several hold() to returns, which cannot be processed further. I shall admit, that this can be misdone, so please check. Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv(a)maths.leeds.ac.uk www: http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://www.worldscientific.com/worldscibooks/10.1142/p835

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Invitation to connect on LinkedIn
by Frank Greenhalgh 12 Jul '13

12 Jul '13

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is_ex_the_function
by morusaka＠libero.it 02 Feb '13

02 Feb '13

Hi, I can't understand why, when I try to use is_ex_the_function with the power function, I get a: >> error: ‘power_SERIAL’ was not declared in this scope My code is something like this: symbol x("x"); ex expr = power(x, 2); std::cout << expr << std::endl; std::cout << is_ex_the_function(expr, power) << std::endl; I get my error on line 4. On the other hand, everything works fine with: symbol x("x"); ex expr = sin(x); std::cout << expr << std::endl; std::cout << is_ex_the_function(expr, sin) << std::endl; Could you please help me? Thank you, Luca-

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[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-383-ge45f9fc
by git＠ginac.de 23 Jan '13

23 Jan '13

This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "GiNaC -- a C++ library for symbolic computations". The branch, master has been updated via e45f9fca76b81e01ffa5edc417c29538fa05147b (commit) from 47522fcd15579cade744182eb0c714331ca230c7 (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit e45f9fca76b81e01ffa5edc417c29538fa05147b Author: Richard Kreckel <kreckel(a)ginac.de> Date: Wed Jan 23 09:19:26 2013 +0100 Add symbol::set_TeX_name(string) member function. This allows setting a symbol's TeX-name after construction. ----------------------------------------------------------------------- Summary of changes: ginac/symbol.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

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Invitación para conectarse en LinkedIn
by Jose Antonio Garcia Peiro 19 Sep '12

19 Sep '12

LinkedIn ------------ Me gustaría añadirte a mi red profesional en LinkedIn. -Jose Antonio Jose Antonio Garcia Peiro Estudiante de Universidad Miguel Hernández de Elche Murcia y alrededores, España Confirma que conoces a Jose Antonio Garcia Peiro: https://www.linkedin.com/e/-smpzss-h79z96aq-37/isd/4281103251/npAG8Ge4/?hs=… -- Estás recibiendo invitaciones a conectar. Haz clic para darte de baja: http://www.linkedin.com/e/-smpzss-h79z96aq-37/pQQaivesQERn6ZpSpQQtivesQEgGd… (c) 2012 LinkedIn Corporation. 2029 Stierlin Ct, Mountain View, CA 94043, EE.UU.

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Fwd: Add method ex::symbols for obtaining all symbols appearing in an expression
by Timo Kluck 11 Sep '12

11 Sep '12

On ma, aug 13, 2012 at 9:02 , Richard B. Kreckel <kreckel(a)ginac.de> wrote: >Wouldn't it be better to go one step further and cache those variables when > the variables() function is first used? This avoids quite a lot of overhead in > space and time! And then, variables() wouldn't have to be a member > function, right? That is probably best, especially in the light of the (x+y) - y example that Alexei mentioned. I could easily do that in Sage, but I think it wouldn't help in my case because I'm constructing so many expressions. However, I'm thinking it may make sense to do that in GiNaC, because from what I've seen it has some sort of a copy-on-right mechanism for subexpressions? As in: f = sin(x+y) g = f * cos(x-y) h = f * tan(z) will make g and h share the instance (and therefore the cache!) for f? Please correct me if I've misunderstood that. But if it has, this is abstracted away in Sage, so caching the variables() function in Sage would have much less benefit than caching it in GiNaC. I'm not sure whether this will actually give me any speed benefit in practice, because even though I'm using very similar subexpressions over and over again, I'm not sure if I could construct them as the same object without writing really awkward code. I'm interested in your opinions, though. So my next question is: would you accept a patch implementing a recursive, cached version of symbols(), for Sage to call directly, and then have responsibility for optimizing / caching that going to the level of GiNaC? I would normally think that it would be a method of ex (and basic). Where would you say the cache lives if it where a global function? Timo

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