Hi Sandeep, As it was already noted here, the cause of the problem is that one of these two groups is a permutation group and the other - pc group. The GAP manual has a section "Saving a Pc Group" which may help you:
http://www.gap-system.org/Manuals/doc/ref/chap46.html#X85696AB9791DF047 - see GapInputPcGroup there. Also, for pc groups you may use the pair of functions CodePcGroup and PcGroupCode, see them here: http://www.gap-system.org/Manuals/doc/ref/chap46.html#X8041C2D88721EEA9 These were invented to store large libraries of small groups, and for really huge groups, they will may work slow. However, GapInputPcGroup performs quite well - I've found the log file for a group of order 3^728 which I was saving several years ago. The group was saved in 9 seconds and restored in 12 seconds, and the file size was "only" 6.5 MB (gzipped - 1.5 MB): gap> PrintTo( "save", GapInputPcGroup( V, "V729_13" ) ); gap> time; 9217 gap> Read("save"); #I A group of order 2209395351413957253683909547381599161963288912918954731542644224734870827044293093746906\ 7135836134418530028589701635375804525993982486739360716170312948236428294558462634156750\ 2928525358477130679078983517688062896651637532904132693253013488158239242149787728540685\ 561563573806847600207803782218928387605966850445847423444996735145737566710612948961 has been defined. #I It is called V729_13 gap> time; 12154 gap> Hope this helps, Alexander On 11 Feb 2015, at 14:05, Sandeep Murthy <s.mur...@mykolab.com> wrote: > Hi > > I am trying to use the IO_PickleToString() method from the SCSCP package > to test out how GAP serialises group objects. This does not appear to be > working as expected on the isomorphic groups Sym(3) and D_6 (dihedral group). > > gap> IO_PickleToString( SymmetricGroup( 3 ) ); > "PRMGILIS\>2PERM\>7(1,2,3)PERM\>5(1,2)INTG\>16FAIL” > > This looks OK but for D_6 it fails: > > gap> IO_PickleToString( DihedralGroup( 6 ) ); > Error, no method found! For debugging hints type ?Recovery from NoMethodFound > Error, no 1st choice method found for `IO_Pickle' on 2 arguments called from > IO_Pickle( s, obj ); called from > <function "IO_PickleToString">( <arguments> ) > called from read-eval loop at line 20 of *stdin* > you can 'quit;' to quit to outer loop, or > you can 'return;' to continue > brk> > > Why is this? Both should return OpenMath strings. > > Sandeep > _______________________________________________ > Forum mailing list > Forum@mail.gap-system.org > http://mail.gap-system.org/mailman/listinfo/forum _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
