On Tue, Feb 16, 2010 at 9:39 PM, Kwankyu <ekwan...@gmail.com> wrote: > 1. Why is the module at such an obscure place as "Combinatorics/ > Combinatorial Species"? I think it should be with the power series > module.
It occurs there since it was written to since the species code needed it. It was not necessarily written for general use which is why it's not with the rest of the power series. > 2. In the following > > sage: L.<t>=LazyPowerSeriesRing(QQ) > sage: s=L([1,2]) > sage: s > O(1) > sage: s.coefficients(10) > [1, 2, 2, 2, 2, 2, 2, 2, 2, 2] > sage: s=L([1,2,0]) > sage: s.coefficients(10) > [1, 2, 0, 0, 0, 0, 0, 0, 0, 0] > > Is this difference intended? I think, the first input notation may > cause bugs rather than be useful. Why is "s" O(1)? Isn't it > O(2)=O(t^2)? It displays as O(1) since none of the coefficients have been "computed". Once the coefficients are computed, then it will display as you think it should. sage: L.<t>=LazyPowerSeriesRing(QQ) sage: s=L([1,2]); s O(1) sage: s.coefficient(0); s 1 1 + O(x^1) sage: s.coefficient(1); s 2 1 + 2*t + O(x^2) sage: s.coefficient(2); s 2 1 + 2*t + 2*t^2 + 2*t^3 + 2*t^4 + ... When a list as given as input, the last entry of the list always repeats. > 3. How should I understand the following? What are the definitions of > "aorder" and "order"? > > sage: s=L([1,2,0]) > sage: s.get_aorder() > 0 > sage: s.get_order() > Unknown series order The order is the power of the variable for which the first nonzero coefficient appears. Aorder stands for approximate order -- this is the "best known" order of the power series without computing any coefficients. The order is often unknown if the coefficients of the series have not been computed. sage: s=L([0,1,2]); s O(1) sage: s.get_aorder(); s.get_order() 0 Unknown series order sage: s.coefficient(0) 0 sage: s.get_aorder(); s.get_order() 1 Unknown series order sage: s.coefficient(1) 1 sage: s.get_aorder(); s.get_order() 1 1 --Mike -- 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 For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
