Re: opposite of partition

*To*: mathgroup at smc.vnet.net*Subject*: [mg57604] Re: opposite of partition*From*: Bill Rowe <readnewsciv at earthlink.net>*Date*: Wed, 1 Jun 2005 06:05:00 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

On 5/31/05 at 5:00 AM, guyi1 at netvision.net.il (Guy Israeli) wrote: >How do I do the opposite of partition quickly? >for example: >l1= {{a, b, c, d, e}, {f, g, h, i, j}, {k, l, m, n, o}, {p, q, r, >s, t}, {u, v, w, x, y}} >and then if I partition it to blocks will result in >{{{{a, b}, {f, g}}, {{c, d}, {h, i}}}, {{{k, l}, {p, q}}, {{m, n}, >{r, s}}}} >flattening it won't help, and its messy to do it by taking all >first lines of the blocks, then second.. >How can I do it quickly? The question is what is it you want to do? Are you attempting to get the output you show after your "if I partition.." from l1? If so, the following does the trick Transpose[Partition[#, 2]&/@ Transpose[Partition[#1, 2]&/@ l1]] {{{{a, b}, {f, g}}, {{c, d}, {h, i}}}, {{{k, l}, {p, q}},{{m, n}, {r, s}}}} -- To reply via email subtract one hundred and four