Re: Sort a List, in a List of Lists of Lists
- To: mathgroup at smc.vnet.net
- Subject: [mg113804] Re: Sort a List, in a List of Lists of Lists
- From: Patrick Scheibe <pscheibe at trm.uni-leipzig.de>
- Date: Sun, 14 Nov 2010 06:06:46 -0500 (EST)
Hi, if you take negative numbers for the level spec than it's (in the case of -2) the second level "from the innerst level in outward direction" l = {{{{4}}}}; Map[f, l, {2}] Map[f, l, {-2}] Cheers Patrick On Sat, 2010-11-13 at 14:03 +0100, leigh.pascoe at inserm.fr wrote: > Ah zut! That's the first thing I tried of course, after scanning the > help pages. However I neglected to notice the difference between {2} > and (2) (very difficult to distinguish on my monitor). It's curious > that the level can be specified by either 2 or -2. Thanks in any case. > > LP > > Quoting Patrick Scheibe <pscheibe at trm.uni-leipzig.de>: > > > Hi, > > > > it's the function Map: > > > > l = {{{1, 2}, {2, 1}, {1, 1}}, {{1, 1}, {1, 1}, {1, 2}}, {{2, 1}, {2, > > 2}, {1, 2}}, {{2, 2}, {1, 2}, {2, 2}}, {{1, 1}, {2, 1}, {1, > > 2}}, {{1, 2}, {2, 2}, {2, 2}}}; > > Map[Sort, l, {-2}] > > > > Cheers > > Patrick > > > > On Sat, 2010-11-13 at 00:59 -0500, leigh.pascoe at inserm.fr wrote: > >> Dear Mathgroup, > >> > >> I have a lsit of Lists of Lists: > >> > >> {{{1,2},{2,1},{1,1}},{{1,1},{1,1},{1,2}},{{2,1},{2,2},{1,2}},{{2,2},{1,2},{2,2}},{{1,1},{2,1},{1,2}},{{1,2},{2,2},{2,2}}} > >> > >> I would like to sort the elements in the lowest level of brackets to give > >> > >> {{{1, 2}, {1, 2}, {1, 1}}, {{1, 1}, {1, 1}, {1, 2}}, {{1, 2}, {2, > >> 2}, {1, 2}}, {{2, 2}, {1, 2}, {2, 2}}, {{1, 1}, {1, 2}, {1, > >> 2}}, {{1, 2}, {2, 2}, {2, 2}}} > >> > >> i.e retaining the same structure with the paired elements in the > >> original order. I can't seem to get the syntax right to do this apart > >> from the obvious > >> > >> {{Sort[{1, 2}], Sort[{2, 1}], Sort[{1, 1}]}, {Sort[{1, 1}], > >> Sort[{1, 1}], Sort[{1, 2}]}, {Sort[{2, 1}], Sort[{2, 2}], > >> Sort[{1, 2}]}, {Sort[{2, 2}], Sort[{1, 2}], > >> Sort[{2, 2}]}, {Sort[{1, 1}], Sort[{2, 1}], > >> Sort[{1, 2}]}, {Sort[{1, 2}], Sort[{2, 2}], Sort[{2, 2}]}} > >> > >> I must have a blind spot for the correct command. Can someone please > >> help me with what should be a straightforward sort. As I want to carry > >> this out on several hundred thousand pairs I need a more efficient > >> command. Thanks in advance. > >> > >> LP > >> > >> ---------------------------------------------------------------- > >> This message was sent using IMP, the Internet Messaging Program. > >> > >> > >> > > > > > > > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. > >