I am taking the liberty of forwarding this to sage-devel since it seems much too important for just sage-nt. OK, so that was my machine David locked up (apparently!). It has 128GB of RAM so does not easily run out...
John ---------- Forwarded message ---------- From: daveloeffler <dave.loeff...@gmail.com> Date: 10 March 2010 15:33 Subject: [sage-nt] Embeddings into QQbar hang To: sage-nt <sage...@googlegroups.com> Is there any reason why one shouldn't be able to work with number fields embedded into QQbar? Since our QQbar class permits exact calculation, but has a canonical embedding into CC, it seems the natural place for the "default embeddings" of cyclotomic fields, quadratic fields and so on. I was playing with this a bit, and found a bug that locked up our research group's server so hard it was out of action for 24 hours. sage: QuadraticField(-7,'a',embedding=QQbar(-7).sqrt()) Number Field in a with defining polynomial x^2 + 7 That's all well and good, but if I then type *exactly the same command again*, Sage locks up totally! It becomes completely unresponsive (Control-C doesn't work) and the memory usage climbs until the machine jams up totally, unless you can kill it quickly from another console session. tried running this with the "trace" command, and it gets as far as computing the square root the second time round, but then gets locked up what looks like the beginning of an infinite loop involving the files sage.misc.function_mangling, sage.misc.cachefunc, and sage.categories.category -- I think it's trying to compute some join operation on categories, but what that has to do with computing the square root of -7 is a mystery to me. Does anyone know what's going on here? -- You received this message because you are subscribed to the Google Groups "sage-nt" group. To post to this group, send an email to sage...@googlegroups.com. To unsubscribe from this group, send email to sage-nt+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sage-nt?hl=en-GB. -- 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
