- GiNaC-devel - ginac.de

[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-338-gf9afb6a
by git＠ginac.de 15 May '11

15 May '11

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 f9afb6aca6a971650dff63b11ca8c2ef18506690 (commit) from e16348f2f6edb1747dca9e4c47300e0436eea617 (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 f9afb6aca6a971650dff63b11ca8c2ef18506690 Author: Richard Kreckel <kreckel(a)ginac.de> Date: Sun May 15 18:40:44 2011 +0200 Fix mul::conjugate(). Overwrite conjugate() for mul objects because the base class's conjugate function is incorrect at branch cuts when exponents are fractional (roots). This has been reported as Sage #10964. While at it, fix some funny indentation and remove unneeded tests. ----------------------------------------------------------------------- Summary of changes: check/exam_paranoia.cpp | 15 +++++++++++++++ ginac/expairseq.cpp | 4 +--- ginac/expairseq.h | 4 ++-- ginac/inifcns_trans.cpp | 2 +- ginac/mul.cpp | 32 ++++++++++++++++++++++++++++++++ ginac/mul.h | 1 + ginac/pseries.cpp | 6 ++---- 7 files changed, 54 insertions(+), 10 deletions(-) hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

1 0

a clarification regarding the problem with simplify_indexed.
by PG CLARK 14 May '11

14 May '11

In fact the code doesn't even care about the tensor symmetry. This code also fails to terminate. #include <iostream> #include <ginac/ginac.h> using namespace std; using namespace GiNaC; int main() { symbol i_sym("i"), j_sym("j"), k_sym("k"), l_sym("l"), m_sym("m"), n_sym("n"); idx i(i_sym, 2), j(j_sym, 2), k(k_sym, 2), l(l_sym, 2), m(m_sym, 2), n(n_sym, 2); symbol alpha_sym("\\alpha"), beta_sym("\\beta"), gamma_sym("\\gamma"); idx Va(alpha_sym, 3), Vb(beta_sym, 3), Vg(gamma_sym, 3); symbol U1("U1"), U2("U2"), U3("U3"), U4("U4"), U5("U5"), U6("U6"), h("h"); exvector IJKLMNVec; idx IJKLMNIA[] ={i, j, k, l, m, n}; IJKLMNVec.assign (IJKLMNIA,IJKLMNIA+6); ex myEx1 = (indexed(h, IJKLMNVec)*indexed(U1, i, Va)*indexed(U5, m, Vg) *indexed(U3, k, Vb)*indexed(U2, j, Va)*indexed(U4, l, Vb)*indexed(U6, n, Vg)); ex myEx2 = (indexed(h, IJKLMNVec)*indexed(U1, i, Va)*indexed(U1, m, Vg) *indexed(U1, k, Vb)*indexed(U1, j, Va)*indexed(U1, l, Vb)*indexed(U1, n, Vg)); ex myEx3 = (indexed(h, IJKLMNVec)*indexed(U1, i, Va)*indexed(U2, m, Vg) *indexed(U1, k, Vb)*indexed(U2, j, Va)*indexed(U1, l, Vb)*indexed(U2, n, Vg)); // swap comments to see .simplify_indexed() fails in all cases cout << myEx2.simplify_indexed() << endl; //cout << myEx3.simplify_indexed() << endl; //cout << myEx1.simplify_indexed() << endl; return 0; } Could this be an error in simplify_indexed_product? ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

1 0

[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-337-ge16348f
by git＠ginac.de 11 May '11

11 May '11

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 e16348f2f6edb1747dca9e4c47300e0436eea617 (commit) from e7d59ed49503cfe73fdb6038c2c69c87cbde7c24 (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 e16348f2f6edb1747dca9e4c47300e0436eea617 Author: Jens Vollinga <jensv(a)nikhef.nl> Date: Tue May 10 23:44:57 2011 +0200 Updated the news about changes done since the last release (2010-07-06). ----------------------------------------------------------------------- Summary of changes: NEWS | 15 +++++++++++++++ 1 files changed, 15 insertions(+), 0 deletions(-) hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

1 0

[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-336-ge7d59ed
by git＠ginac.de 09 Apr '11

09 Apr '11

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 e7d59ed49503cfe73fdb6038c2c69c87cbde7c24 (commit) from 286b0d93528e35957a50c51343e0b4a9bc623bce (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 e7d59ed49503cfe73fdb6038c2c69c87cbde7c24 Author: Vladimir V. Kisil <kisilv(a)maths.leeds.ac.uk> Date: Sat Apr 9 12:40:38 2011 +0200 Add conjugate() methods to functions cosh, sinh, tanh. ----------------------------------------------------------------------- Summary of changes: ginac/inifcns_trans.cpp | 21 +++++++++++++++++++++ 1 files changed, 21 insertions(+), 0 deletions(-) hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

1 0

Conjugated cosh and sinh
by Vladimir V. Kisil 08 Apr '11

08 Apr '11

Dear All, Analysing a failure of my code I found the reason in the absence of conjugate() method for cosh and sinh functions. Is there a fundamental reason for this? Or shall I prepare a patch defining them similarly to this: static ex cosh_conjugate(const ex & x) { // conjugate(cosh(x))==cosh(conjugate(x)) return cosh(x.conjugate()); } Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv(a)maths.leeds.ac.uk -- www: http://www.maths.leeds.ac.uk/~kisilv/

2 2

[PATCH] Fix unsigned character bugs in ginac-1.5.8
by Martin Guy 06 Apr '11

06 Apr '11

Hi There are a couple of bugs that stop ginac from working on machines whose characters are unsigned by default (where a conversion to int goves a value 0-255). It's the classic "char c = getchar(); if (c == EOF)" with result that it doesn't detect EOF on unsigned machines, or exits prematurely on signed machines if it reads a character 255. The fixes are to replace "char" with "int" so that all 257 possible return values are correctly handled. The attached patch for ginac-1.4.3 still applies to 1.5.8 Cheers M

3 4

Nested Polynomial Algorithm
by Frank Greenhalgh 11 Mar '11

11 Mar '11

The following algorithm creates a nested polynomial to minimize the number of multiplications and additions in evaluating a polynomial at some given point, x. I use it to reduce my Finite Element Method basis functions. //Converts an *expanded* polynomial into a nested polynomial for efficient evaluation at points ex nested_polynomial( ex polynomial, realsymbol x ){ //result is returned to the user, highest order is the peeled off highest order term of the polynomial ex result=0, highest_order; //While the polynomial is not empty continue peeling off the highest degree while( polynomial.degree( x ) != 0 ){ //get the highest order term highest_order = polynomial.lcoeff(x) * pow( x, polynomial.degree(x) ); //add to nest result+= highest_order.lcoeff( x ); //remove the highest order term from the expanded polynomial polynomial-=highest_order; //multiply the result by the proper amount of x's result*=pow(x, highest_order.degree(x)- polynomial.degree(x) ); } //correct for forgotten 0th order terms result+=polynomial.lcoeff(x); return result; } Example: polynomial = 10*x^5 + 3*x^3 + 1; the function would return (with polynomial and x as inputs): 1+x^3*(3+x^2*10) which minimizes the number of multiplications and additions we need to do in evaluation. The first polynomial form needs 5+3=8 multiplications and 2 additions, while the second form needs 2+3=5 multiplications and 2 additions.

1 0

Creating non-commutative symbols
by Jan 19 Feb '11

19 Feb '11

Hi Alexei, would you accept this patch to make creation of non-commutative symbols easier? Problem: The GiNaC info documentation claims: "Both symbols and user-defined functions can be specified as being non-commutative" Currently this is only possible by defining a new subclass of symbol and overloading return_type(). Solution: Added unsigned rtype to class symbol Overloaded return_type() Modified constructors (including realsymbol and possymbol), printing and archiving accordingly ------------ Now my next question is (after applying the above patch) whether there is a bug in ncmul::eval(). I created this test program #include <ginac/ginac.h> using namespace GiNaC; int main() { symbol M1("M1", "M1", return_types::noncommutative); symbol x("x"), y("y"); matrix M2(2,2); M2 = x, 0, y, 0; symbol M3("M3", "M3", return_types::noncommutative); ex nc; nc = M1 * M2; // Produces a mul !! nc = M1 * M1; // Produces a ncmul nc = M1 * M3; // Produces a ncmul nc = nc.subs(M1 == M2); // Produces a mul !! } As you can see, the assignment sometimes creates a mul when a ncmul should be created. Best regards, Jan

3 6

Non-commutative symbols
by Jan 12 Feb '11

12 Feb '11

Hi, the GiNaC info documentation claims: Both symbols and user-defined functions can be specified as being non-commutative. I couldn't figure out how to create a non-commutative symbol, though, except by defining a new subclass of symbol and overloading return_type() Any hints? Thanks, Jan

1 0

release
by Jens Vollinga 04 Feb '11

04 Feb '11

Hi, looks like I could do a 1.5.9 release this weekend. Any objections? Regards, Jens

3 15