On Thursday 27 October 2011, Simon King wrote: > Hi! > > I just found the following: > sage: P.<x,y,z> = QQ[] > sage: def test1(x,y,z): > ....: for i in range(100): > ....: p = (x+y+z)^i > ....: > sage: def test2(x,y,z): > ....: x = singular(x) > ....: y = singular(y) > ....: z = singular(z) > ....: for i in range(100): > ....: p = (x+y+z)^i > ....: > sage: %time test1(x,y,z) > CPU times: user 2.66 s, sys: 0.00 s, total: 2.66 s > Wall time: 2.67 s > sage: %time test2(x,y,z) > CPU times: user 0.15 s, sys: 0.08 s, total: 0.23 s > Wall time: 1.94 s > > The timings were obtained with sage-4.6.2. > > So, replacing libSingular with Singular-via-pexpect saves much of the > computation time. > > Is that something to worry about?
Yes! I can confirm this behaviour. The problem doesn't seem to be restricted to __pow__, i.e. replacing ^i by products also gives slower results when using using libSingular. However, mod p it seems libSingular wins. Hence my guess: we are using different memory allocation functions for GMP and these functions might be slower (for Singular's use case)? Cheers, Martin -- name: Martin Albrecht _pgp: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99 _otr: 47F43D1A 5D68C36F 468BAEBA 640E8856 D7951CCF _www: http://martinralbrecht.wordpress.com/ _jab: martinralbre...@jabber.ccc.de -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
