Hello, Not sure whether it is related or not. In the file sage/rings/function_field/function_field.py there are two doctests that take respectively much shorter and much longer than what is written. Namely
Trying (line 58): TestSuite(L).run() # long time (8s on sage.math, 2012) Expecting nothing ok [3.16 s] Trying (line 59): TestSuite(M).run() # long time (52s on sage.math, 2012) Expecting nothing ok [141.39 s] so it is roughly /2 and x3 with respect to the timings in the comments! These differences certainly come from something that has changed since 2012... Vincent 2015-01-26 21:13 UTC+01:00, Stefan <stefanvanz...@gmail.com>: > Hi all, > > I wrote some code for product rings a while back, and went back to it for > more computations. My computations took vastly longer, and it seems the > culprit is the inverse function in my ring. > > The product code ring is here: > > http://pastebin.com/V2Cx6gVB > > I ran the following test code: > > ===== > from sage.matroids.advanced import * > load /path/to/product_ring.py > > H5 = ProductRing((GF(5), GF(5), GF(5), GF(5), GF(5), GF(5))) > print H5 > > H5CrossRatios = set([H5(1)]) > H5CrossRatios.update([H5(x) for x in > Permutations([2, 2, 3, 3, 4, 4])]) > L = list(H5CrossRatios) > print len(H5CrossRatios) > > timeit(""" > s = 0 > for i in xrange(91): > for j in xrange(91): > for k in xrange(30): > s = s + L[i] + (L[j])^(-1) * L[k]""", number=1, > repeat=1) > ===== > > In Sage 5.12 this takes 6.41 seconds on my computer; in Sage 6.5.beta5 it > takes 117 seconds. > > The culprit is the inverse, if you do just addition and multiplication the > code runs in the same amount of time. So... > > * did I implement my ring wrong, and did it just happen to work better in > the past? > * can I change my ring code to speed this back up? > * can you point to a change in Sage that could have caused this? And help > me think about a way to fix it? > > Cheers, > > Stefan > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
