Dear Alexander, Thank you so much for helping and I think my problem of this character degree stuff solved now!
Best wishes, Jiayue 在2016-12-17 23:58:42,齐嘉悦<[email protected]>写道： > Dear Forum, > > Jiayue asked: > > > Em.. here is a question I have about GAP: > > > > Is there any operations like "AllSmallGroupsOfCharacterDegrees([...])"? > > > > How do we find the certain groups in GAP database(the SmallGroup Id will be > > fine) > > holding the given character degrees? > > > The operation `AllSmallGroups’ can select for groups satisfying certain > functions, e.g the result of the function `CharacterDegrees’. For example, to > get all groups of order 32 with 4 characters of degree and 16 linear > characters, one could use: > > AllSmallGroups(Size,32,CharacterDegrees,[[[1,16],[2,4]]]); > > (Note that, as the result is a list, we need to wrap it in a list once more > to avoid GAP interpreting it as a collection of values, alternatively one > could use it as: > > AllSmallGroups(Size,32,x->CharacterDegrees(x)=[[1,16],[2,4]],true); > > Note that the character degrees are not stored precomputed in the library, so > GAP will have to compute them on the fly for all groups in the otherwise > specified range. So doing this test for order 256 could take a long time. > > If you do not care about multiplicities, you could take the degrees only with > a small list operation, that is: > > occurringDegrees:=g->List(CharacterDegrees(g),x->x[1]); > AllSmallGroups(Size,32,occurringDegrees,[[1,2]]); > > would return the groups of order 32 with characters only of degree 1 and 2. > > Regards, > > Alexander Hulpke > > -- Colorado State University, Department of Mathematics, > Weber Building, 1874 Campus Delivery, Fort Collins, CO 80523-1874, USA > email: [email protected], Phone: ++1-970-4914288 > http://www.math.colostate.edu/~hulpke > > _______________________________________________ Forum mailing list [email protected] http://mail.gap-system.org/mailman/listinfo/forum
