Hi, David, Thanks a lot. I tried trace_dual_basis? to find out the meaning. I didn't realize I should use K.trace_dual_basis?
Thanks. :) Cindy On Wednesday, September 5, 2012 5:15:19 PM UTC+8, David Loeffler wrote: > > On 5 September 2012 09:34, Cindy <cindy42...@gmail.com <javascript:>> > wrote: > > Hi, David, > > > > Could you please explain a little bit about the code? > > Sure, but you should make a little effort to play with it yourself for > a bit first. > > > For the example you use, it seems I is an ideal above 17, what does [0] > > mean? > > The command K.primes_above(...) returns a list of the prime ideals > above the given rational prime. The [0] selects the first (zeroth?) > from the list. So yes, I is an ideal above 17 which I am just using as > an example (any number field ideal, except the zero ideal, would work > here). There are lots of examples like this in the Sage documentation. > > > In the end do we get a basis of the dual of I? > > Yes, that's the whole point of the exercise :-). Did you read the > documentation for "trace_dual_basis"? You should know that you can get > documentation on any method of any Sage object by typing its name then > ?, e.g. > > sage: K.trace_dual_basis? > > will tell you lots more about this method. > > > Why do we need to put > > I.basis() in the bracket of trace_dual_basis? > > Because trace_dual_basis takes a list of generators as its argument -- > it can calculate the trace dual of any Z-submodule of K, it needn't be > an ideal. > > Regards, David > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To post to this group, send email to sage-support@googlegroups.com. To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support?hl=en.
