OK so thinking about it, even though your code is beautifully compact and elegant, I think I am going to have to revert a little to the "outer-inner-loop" structure in order to achieve what I need. Namely, instead of storing "used" vectors, I store "used" bases and search through the remaining orthogonal sets exhaustively. Otherwise I cannot get at the bases which may share a vector with another basis but have different "xRy" properties. I am trying to program this now - please feel free to tell me a better way!!
Thanks and regards Gary On Sat, Mar 30, 2013 at 9:09 PM, Gary McConnell <garymako...@googlemail.com>wrote: > Thanks again Jason - that seems to do the trick - now I just have to > figure out the equivalent of the old BASIC "goto 10" to start your loop > again!! > > So I understand something of what is going on, could you please tell me > why the tuple thing is necessary for the "used" set but the vectors are > necessary for the "bases": ie why can we not use a vector structure for > "used"? > > > On Sat, Mar 30, 2013 at 7:22 PM, Jason Grout > <jason-s...@creativetrax.com>wrote: > >> On 3/30/13 1:43 PM, Gary McConnell wrote: >> >>> OK now I'm back in a familiar nightmare - if I set the vectors to be >>> immutable then I cannot treat them as vectors because they seem to be of >>> "NoneType" or something so have no length etc etc; however I cannot /not >>> /set them to be immutable if I wish to work through a list consisting of >>> >>> those very vectors. I remember now that this is what drove me to abandon >>> anything other than the plain old nested subroutines a long time ago, >>> because I couldn't reverse-engineer my way out of this conundrum. Is >>> there something simple that will put me out of my misery please?!! >>> >>> >> Sure; convert to tuples to store into the set and test membership in the >> set. I've updated the gist: >> >> https://gist.github.com/**jasongrout/5276508<https://gist.github.com/jasongrout/5276508> >> >> >> Thanks, >> >> Jason >> >> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "sage-support" group. >> To unsubscribe from this topic, visit https://groups.google.com/d/** >> topic/sage-support/**GFJdjFvKCvo/unsubscribe?hl=en<https://groups.google.com/d/topic/sage-support/GFJdjFvKCvo/unsubscribe?hl=en> >> . >> To unsubscribe from this group and all its topics, send an email to >> sage-support+unsubscribe@**googlegroups.com<sage-support%2bunsubscr...@googlegroups.com> >> . >> To post to this group, send email to sage-support@googlegroups.com. >> Visit this group at >> http://groups.google.com/**group/sage-support?hl=en<http://groups.google.com/group/sage-support?hl=en> >> . >> For more options, visit >> https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out> >> . >> >> >> > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
