Hello folks, somewhere since 2.8.3 we introduced a new bug that seems to affect computing the power of matrices when the entries are multivariate polynomials with rational coefficients:
[EMAIL PROTECTED] sage-2.8.14$ ./sage ---------------------------------------------------------------------- | SAGE Version 2.8.14, Release Date: 2007-11-24 | | Type notebook() for the GUI, and license() for information. | ---------------------------------------------------------------------- sage: R.<x,y>=MPolynomialRing(QQ,2) sage: A = matrix([[Integer(1),x], [y,Integer(1)]]) sage: A [1 x] [y 1] sage: A*A [x*y + 1 2*x] [ 2*y x*y + 1] sage: A**2 ------------------------------------------------------------ Unhandled SIGSEGV: A segmentation fault occured in SAGE. This probably occured because a *compiled* component of SAGE has a bug in it (typically accessing invalid memory) or is not properly wrapped with _sig_on, _sig_off. You might want to run SAGE under gdb with 'sage -gdb' to debug this. SAGE will now terminate (sorry). ------------------------------------------------------------ When using ZZ as a coefficient ring the problem goes away: [EMAIL PROTECTED] sage-2.8.14$ ./sage ---------------------------------------------------------------------- | SAGE Version 2.8.14, Release Date: 2007-11-24 | | Type notebook() for the GUI, and license() for information. | ---------------------------------------------------------------------- sage: R.<x,y>=MPolynomialRing(ZZ,2) sage: A = matrix([[Integer(1),x], [y,Integer(1)]]) sage: A [1 x] [y 1] sage: A*A [x*y + 1 2*x] [ 2*y x*y + 1] sage: A**2 [x*y + 1 2*x] [ 2*y x*y + 1] sage: A**10 [x^5*y^5 + 45*x^4*y^4 + 210*x^3*y^3 + 210*x^2*y^2 + 45*x*y + 1 10*x^5*y^4 + 120*x^4*y^3 + 252*x^3*y^2 + 120*x^2*y + 10*x] [ 10*x^4*y^5 + 120*x^3*y^4 + 252*x^2*y^3 + 120*x*y^2 + 10*y x^5*y^5 + 45*x^4*y^4 + 210*x^3*y^3 + 210*x^2*y^2 + 45*x*y + 1] sage: These issues seems to rely on matrices, i.e. "just" polynomials does work: [EMAIL PROTECTED] sage-2.8.14$ ./sage ---------------------------------------------------------------------- | SAGE Version 2.8.14, Release Date: 2007-11-24 | | Type notebook() for the GUI, and license() for information. | ---------------------------------------------------------------------- sage: sage: R.<x,y>=MPolynomialRing(QQ,2) sage: sage: f = x^3 + y sage: f*f x^6 + 2*x^3*y + y^2 sage: f^2 x^6 + 2*x^3*y + y^2 sage: f**2 x^6 + 2*x^3*y + y^2 sage: f**10 x^30 + 10*x^27*y + 45*x^24*y^2 + 120*x^21*y^3 + 210*x^18*y^4 + 252*x^15*y^5 + 210*x^12*y^6 + 120*x^9*y^7 + 45*x^6*y^8 + 10*x^3*y^9 + y^10 sage: Exiting SAGE (CPU time 0m0.03s, Wall time 0m29.97s). And ideas? I know malb is on his way to Paris shortly, but I have wasted a tremendous amount of time playing with 2.8.14 on Solaris instead of doing "real" work since I wanted 2.8.15 to come close to compilable out of the box on Solaris. We might get close to compilable, but are certainly way off on the doctests at the moment Cheers, Michael --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
