[sage-support] composition in power series ring

2012-10-27 Thread Martin Mereb
Hi! I found the following issue: sage: R.=PowerSeriesRing(QQ) sage: f=u+O(u,v,t,T)^200 sage: g=f-u sage: g(u^4,v^4,t^4,T^4) --- AttributeErrorTraceback (most recent call last) /home/tincho/ in ()

[sage-support] Re: Unable to Solve Simple Problem

2012-10-27 Thread Dima Pasechnik
On 2012-10-27, Robert Dodier wrote: > On 2012-10-26, Jan wrote: > >> I have a similar problem I can't solve >> d==b*sqrt(d)+c >> for d. All suggestions (to_poly_solve, use_grobner) did not work. > > For the record, here's what I get with Maxima 5.28.0. I think > to_poly_solve has been updated in

[sage-support] Re: Unable to Solve Simple Problem

2012-10-27 Thread Robert Dodier
On 2012-10-26, Jan wrote: > I have a similar problem I can't solve > d==b*sqrt(d)+c > for d. All suggestions (to_poly_solve, use_grobner) did not work. For the record, here's what I get with Maxima 5.28.0. I think to_poly_solve has been updated in the not so distant past so maybe Sage is using

Re: [sage-support] Re: Unable to Solve Simple Problem

2012-10-27 Thread Doaa El-Sakout
Please, could you explain more what is the problem. According to my understand. b and c are two parameters and you want to solve for d. and you try to use grobner basis, but what I know grobner basis for polynomial and this is not polynomial because the square root. So , you can write d=y^2, y^2==b

[sage-support] Re: Strange results in DiGraph.girth()

2012-10-27 Thread P Purkayastha
On 10/27/2012 08:34 PM, Georgi Guninski wrote: Got results with DiGraph.girth() which appear inconsistent to me. girth() returns 3 and powers of the adjacency matrix suggest there are no directed triangle cycles and couldn't s see a directed triangle cycle on the plot of the digraph. sage: GR=Di

[sage-support] Strange results in DiGraph.girth()

2012-10-27 Thread Georgi Guninski
Got results with DiGraph.girth() which appear inconsistent to me. girth() returns 3 and powers of the adjacency matrix suggest there are no directed triangle cycles and couldn't s see a directed triangle cycle on the plot of the digraph. sage: GR=DiGraph('FWE@_WF@o?');M=GR.adjacency_matrix() sage: