Re: Partitioning 1-D list into 2-D Matrix

• To: mathgroup at smc.vnet.net
• Subject: [mg29780] Re: Partitioning 1-D list into 2-D Matrix
• From: "Orestis Vantzos" <atelesforos at hotmail.com>
• Date: Sun, 8 Jul 2001 20:35:55 -0400 (EDT)
• Organization: National Technical University of Athens, Greece
• References: <9i6ao4\$ol6\$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```Why use Partition 2 times!?!
Partition[b,5] returns the matrix you want.
Generaly a single application of Partition to a vector will return a
(rectangular) matrix. As a second argument to Partition you can supply any
divisor of the Length of the vector.
Orestis

"Krautschik, Chris G" <krautschikc at intel.co.jp>
>
> b=Range[1,20]
> {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}
>
> I would like to arrange the list into a 2D array of the following form:
> {{1, 3, 5, 7, 9}, {2, 4, 6, 8, 10}, {11, 13, 15, 17, 19}, {12, 14, 16, 18,
> 20}}
>
> Then
> bb=Partition[Partition[b,2],5]
>  <<...OLE_Obj...>>
> almost does what I want if you view this array in MatrixForm[]. However, I
> would have to somehow get rid of the innner brackets. I am not sure how to
> do that with Flatten[].
>
> I could use brute force and select the elements as follows:
>  <<...OLE_Obj...>>
>  <<...OLE_Obj...>>
>
> I have a feeling there is a much better way to do this.
>