RE: basic operations in matrices
- To: mathgroup at smc.vnet.net
- Subject: [mg34578] RE: [mg34542] basic operations in matrices
- From: Juan Egea Garcia <jeg at um.es>
- Date: Wed, 29 May 2002 02:44:22 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Christian, i´ve make this operation in order to transpose tow rows
Operation[m_List, v_List] := Module[{a},
a = Table[j, {j, Length[m]}] /. v[[1]] -> v[[2]];
b = ReplacePart[a, v[[1]], v[[2]]];
Map[m[[#]] &, b]
]
Note that v = {i,j} (i=1,j=3 in your example).
Another way is use only the Map function in this form
Operaton2[m_List,v_List]:=Map[m[[#]] &,v] in this case v represents the
complete vector, {3,2,1,4} for your example.
You can make in a similar way a function in order to transpose to columns.
=======================================
Juan Egea Garcia
Departamento de Matemática Aplicada
Universidad de Murcia
España
+34 968654243
+34 968367144
-----Mensaje original-----
De: Christian Junk [mailto:junkc at fh-trier.de]
Enviado el: lunes, 27 de mayo de 2002 7:16
Para: mathgroup at smc.vnet.net
Asunto: [mg34542] basic operations in matrices
Hi!
I'm new to Mathematica and I'm searching for an operation, that simply
transpose two rows or columns of a matrix M.
e.g:
Operation[M,{1,3}]
1 1 1 1 3 3 3 3
2 2 2 2 ---> 2 2 2 2
3 3 3 3 1 1 1 1
4 4 4 4 4 4 4 4
Much thanks in advance,
Christian